Multiple Studies Below
"The rates of successful tourniquet application for the CAT, RMT, and SWAT-T were 16.9%, 23.4%, and 10.6% respectively ...
Conclusion: Our pilot study on the intuitive nature of applying commerically available tourniquets found unacceptably high rates of failure."

THE TOURNIQUET GAP: A PILOT STUDY OF THE INTUITIVE PLACEMENT OF THREE TOURNIQUET TYPES BY LAYPERSONS
Elliot M. Ross, MD, MPH, Julian G. Mapp, MD, MPH, Theodore T. Redman, MD, MPH, Derek J. Brown, MD, Chetan U. Kharod, MD, MPH, and David A. Wampler, PHD, LP
Prehospital Research and Innovation in Military and Expeditionary Environments (PRIME2) Research Group, San Antonio, Texas

"... A more recent study from the campaign in Afghanistan found that in 83% of CAT applications distal pulses were present, indicating ineffectiveness...
It was found that the leading cause to failure was applying the device loosely ...
Furthermore, excess wind-lass twists might cause the cat to roll and even break."

CAPT Dean Nachman, MC IDF; MAJ Avi Benov, MC IDF; MAJ Amiram Shovali, MC IDF; MAJ Yavnai Nirit, MC IDF; CAPT Roy Nadler, MC IDF; LT Yitzhak Avraham, MC IDF; COL Elon Glassberg, MC IDF
Slack Reducing Band Improves Combat Application Tourniquet Pressure Profile and Hemorrhage Control Rate
MILITARY MEDICINE, Vol. 182, March/April Supplement 2017

"Medics were generally surprised at how tight a tourniquet must be to stop arterial flow- convert a venous tourniquet into an arterial tourniquet.
Implications for sustainment training should be considered with regard to this life-saving skill."

David R. King, MD; Gwendolyn van der Wilden, MSC; John F. Kragh, Jr., MD; and Lorne H. Blackbourne, MD
Forward Assessment of 79 Prehospital Battlefield Tourniquet Use in the Current War
Journal of Special Operations Medicine Volume 12, Edition 4/Winter 2012

"Between February and May 2010, 1st Battalion, 6th Marines reported a 10% (10/92) breakage rate for tourniquets. "

Justin Weppner, Michael Lang, Robert Sunday, Nicholas Debiasse;
Efficacy of Tourniquets Exposed to the Afghanistan Combat Environment Stored in Individual First Aid Kits Versus on the Exterior of Plate Carriers,
Military Medicine, Volume 178, Issue 3, 1 March 2013, Pages 334–337,
https://doi.org/10.7205/MILMED-D-12-00454

"Initially, 70% successfully applied CAT. ...
After correction, cumulative success rate of 93 and 100% was reached at 990° and 1170°"

Ünlü, Aytekin & Petrone, Patrizio & Güvenç, Inanç & Kaymak, Sahin & Arslan, Gokhan & Kaya, E & Yilmaz, Soner & Aytaç, Cetinkaya & Ege, T & Ozer, Mustafa & Kilic, Selim. (2015).
Combat application tourniquet (CAT) eradicates popliteal pulses effectively by correcting the windlass turn degrees: a trial on 145 participants.
European journal of trauma and emergency surgery : official publication of the European Trauma Society. 43. 10.1007/s00068-015-0582-0.

"A recent analysis of combat casualties indicated a 21% failure rate for the Combat Application Tourniquet (CAT) ... However, even after 4 days of training, one-in-four participants failed in pulse elimination using the CAT"

LCDR Richard Schreckengaust, MC USN; CDR Lanny Littlejohn, MC USN; Gregory J. Zarow, PhD
Effects of Training and Simulated Combat Stress on Leg Tourniquet Application Accuracy, Time, and Effectiveness
MILITARY MEDICINE, 179, 2:114, 2014

"A 14% (7/49) breakage of CATs applied by Marine Regimental Combat Team 3 during operations in Afghanistan ... Several theories have been considered for this difference, including weakening of the tourniquet by exposure to the environment and excessive force in application."
LCDR Richard Childers, Jerlyn C. Tolentino, John Leasiolagi, Nick Wiley, LT Damian Liebhardt, Sean Barbabella, COL John F. Kragh Jr. (2011)
Tourniquets Exposed to the Afghanistan Combat Environment Have Decreased Efficacy and Increased Breakage Compared to Unexposed Tourniquets
MILITARY MEDICINE, 176, 12:1400, 2011

"Ninety one percent of participants achieved effective occlusion pressure with the IST compared with 73.1% with the CAT. Our findings negate the common belief that windlass tourniquets, such as the CAT, are superior for controlling bleeding in thigh injuries."
CPT Yuval Glick; MAJ Ariel Furer; COL Elon Glassberg; LT (Reserve) Roni Sharon, MD; MAJ Ran Ankory
Comparison of Two Tourniquets on a Mid-Thigh Model: The Israeli Silicone Stretch and Wrap Tourniquet vs. The Combat Application Tourniquet
MILITARY MEDICINE, 183, 3/4:157, 2018

"Conclusion: This study demonstrates that the CAT tourniquet is ineffective in controlling arterial blood flow when applied at mid-thigh level. The EMT was successful in a significantly larger number of participants."
David M. Taylor, MBChB, MRCS(Ed), Dip IMC, Gill M. Vater, MBChB, and Paul J. Parker, FRCS, FRCS (Tr+Orth), FIMC
An Evaluation of Two Tourniquet Systems for the Control of Prehospital Lower Limb Hemmorage
The Journal of TRAUMA® Injury, Infection, and Critical Care • Volume 71, Number 3, September 2011

"45 of 179 user performances (25%) were competent. Users who reported high confidence had only a slightly higher chance of achieving competence in tourniquet application ...
The most common reason for failure was excess slack in the CAT's strap (experts 55%, users 39%), and too few turns of the windlass (23% and 31%, respectively) was the second most common reason. "
Baruch EN, Kragh JF Jr, Berg AL, Aden JK Rd, Benov A, Shina A, Shlaifer A, Ahimor A, Glassberg E, Yitzhak A.

Confidence-Competence Mismatch and Reasons for Failure of Non-Medical Tourniquet Users.

2017 Jan-Feb;21(1):39-45. doi: 10.1080/10903127.2016.1209261. Epub 2016 Aug 5.

"The CAT was touted as one of the better windlass tourniquets, with many overall positive subject comments.
However, among the problems identified were a difficulty with the Velcro interfering with initial applications, and a difficulty in securing the windlass after the CAT had been applied. Both of these problems were more prevalent with one-handed applications. "
J. P. Hill, LT, MC, USN L. D. Montgomery, Ph.D. K. W. Hopper, HM1, USN L. A. Roy, LT, MC, USN
Evaluation of Self-Applied Tourniquets for Combat Applications, Second Phase
Marine Corps Systems Command,NEDU Technical Report No. 07-07, 2007 April 03

" Tourniquet application is an easy, fast, and cheap method for prehospital control of perfuse limb injuries and might be live-saving ...
Nevertheless, to minimize complications, ischemic time should be as short as possible"
Dror Lakstein, MD, Amir Blumenfeld, MD, Tali Sokolov, MD, Guy Lin, MD, Roni Bssorai, MD, Mauricio Lynn, MD, and Ron Ben-Abraham, MD

Tourniquets for Hemorrhage Control on the Battlefield: A 4-Year Accumulated Experience

The Journal of TRAUMA Injury, Infection, and Critical Care; 2003;54:S221–S225.

"Pulse elimination was poor for CAT (25% failure) and SOFT-T (60% failure) even in classroom conditions following training. ...
pointing to the need for superior tourniquets and for rigorous deployment preparation training in simulated combat scenarios."
LCDR Richard Schreckengaust, MC USN; CDR Lanny Littlejohn, MC USN; Gregory J. Zarow, PhD
Effects of Training and Simulated Combat Stress on Leg Tourniquet Application Accuracy, Time, and Effectiveness
MILITARY MEDICINE, 179, 2:114, 2014

"The CAT, SAMXT, TMT, and SOFTTW all failed on the 5.08 cm diameter mannequin."
(2018) Abstracts for the 2018 NAEMSP Scientific Assembly
Prehospital Emergency Care, 22:1, 101-150, DOI: 10.1080/10903127.2017.1377791

"The SWAT, TMK9 and RATS were successful stopping the flow of water on all sized mannequins. ...
The CAT, SAMXT, TMT, and SOFTTW all failed on the 5.08 cm diameter mannequin. "
James Vretis, Center for Tactical Medicine Category of Submission: Pediatric
Abstracts for the 2018 NAEMSP Scientific Assembly, Prehospital Emergency Care, 22:1, 123.
https://doi.org/10.1080/10903127.2017.1377791

Elastic Tourniquet Safety
"CONCLUSION: The SRT performed similarly to the classic PT in terms of tolerance and recovery time when applied in in the arm and thigh."
Silicone Ring Versus Pneumatic Cuff Tourniquet: A Comparative Quantitative Study in Healthy Individuals
Arch Orthop Trauma Surg, G. I. Drosos
"On the upper arm, the silicone ring tourniquet was associated with a significantly lower pain score than the pneumatic tourniquet. The incidence of paraesthesia was also lower with the silicone ring tourniquet. ...
the incidence of paraesthesia was again lower with the silicone ring tourniquet."
Pain and Paresthesia Produced by Silicone Ring and Pneumatic Tourniquet
The Journal of Hand Surgery, Vol 36E(3), p. 215‐218, 2010. A Mohan.
"RESULTS: There was no failure of application or cutaneous complications after its removal and no complaints from the young patients at all as well."
The Use of Sterile Tourniquet in Paediatric Orthopaedics
E.E.X.O.T., Volume 61, Number 3, 2010:153‐158. MARKEAS N, et al.
"Patients demonstrated quick application, superior exsanguination and that the device could be placed on the forearm instead of the upper arm. No side effects or complications were noted."
Use of a New Exsanguination Tourniquet in Internal Fixation of Distal Radius Fractures
Techniques in Hand & Upper Extremity Surgery ‐ Volume 13, Number 4, December 2009. Doron Norman
"Provides a better haemostasis as compared to the pneumatic tourniquet."
Use of the S‐MART Tourniquet in Total Elbow Arthroplasty
Mr Arvind Mohan
"SMART™ tourniquet provides a good intraoperative haemostasis and is easy to apply."
S‐MART and Pneumatic Tourniquet in Foot Surgery ‐ A Randomized Controlled Study
Arvind Mohan
"No side effects or ischemic complications were observed. After removal, the skin under the ring was intact in all cases. "
A Novel Elastic Exsanguination Tourniquet as an Alternative to the Pneumatic Cuff in Pediatric Orthopedic Limb Surgery
Journal of Pediatric Orthopaedics B 2006, 15:379–384. Mark Eidelman, Alexander Katzman and Viktor Bialik
"We outline the reasons of why we feel that this device provides a safe and effective bloodless field and the benefits of its use."
The Use of the S‐MART Tourniquet in Hand Surgery: A Safe and Effective Way to Provide a Bloodless Field
Surgery Research and Practice Volume 2014, Article ID 402184, 3 pages O. Templeton‐Ward, J. Feher, and P. Davey
"The data described above clearly document the superior safety track record of the elastic exsanguination tourniquet (S‐MART/HemaClear) over the wide tourniquet ...
The fact that the patient’s skin tolerates the SMART/HemaClear better than the wide tourniquet cuff ...
These features are accompanied by other advantages: the overall lower volume of tissue that is under compression"
Surgical Tourniquets in Orthopaedics
J Bone Joint Surg Am. 2010;92:1318‐1322. (To The Editor). Noam Gavriely
"The SRT ‐ with a pre‐set pressure according to the size and the tension model ‐ is easy to apply. It is sterile, and occupies a narrow area of the limb
...
it is a safe and useful device in orthopaedic operations because of its advantages. (Mostly Hip,Pediatrics, Adults;"
The Silicone Ring Tourniquet in Orthopaedic Operations of the Extremities
Surg Technol Int. 2013 Sep; 23:251‐7. Drosos et al.
"CONCLUSIONS: We conclude that this sterile elastic exsanguination tourniquet is effective and safe in preventing bleeding during (ForeArm Upper arm: dialysis access procedures)"
A Sterile Elastic Exsanguination Tourniquet is Effective in Preventing Blood Loss During Hemodialysis Access Surgery
J Vasc Access 2013;14 (2): 116‐119 Eric Ladenheim et al.
"RESULTS: There was no statistically significant difference in tolerance time between SRT and PT ...
The SRT performed similarly to the classic PT in terms of tolerance and recovery time when applied in the arm and thigh"
Silicone Ring Versus Pneumatic Cuff Tourniquet: A Comparative Quantitative Study in Healthy Individuals
Arch Orthop Trauma Surg. Georgios I. Drosos
sa "...better pain tolerance and produces less parasthesias as compared to pneumatic tourniquet."
Pain Tolerance with a Novel Tourniquet in Hand Surgery ‐ A Comparative Study
Mr Arvind Mohan
"The surgical procedures were under excellent visibility conditions with the SET. The SET was found to be safe for use in trauma"
Safety of Using a Novel Device for Creating a Bloodless Surgical Field in Pediatric Limb Fractures
N. Hous, D. Norman, A. Katzman and M. Eidelman.
"This preliminary study shows that the use of the new silicone ring tourniquet may present with some advantages over the use of a standard pneumatic cuff tourniquet"
Silicone Ring Versus Pneumatic Cuff Tourniquet: A Preliminary Comparative Quantitative Study in Healthy Individuals
7th EFORT Congress, Lisbon, Portugal, June 2005, G. I. Drosos et al. Abstract ID: 2476
"...provided an excellent bloodless field. At follow‐up examination no signs or symptoms were seen at the site of the S‐MART occlusion and no complications were observed in any patient."
Evaluation of a Novel Tourniquet Device for Bloodless Surgery of the Hand
Journal of Hand Surgery (British and European Volume, 2004) 29B: 2: 185–187M. Boiko and M. Roffman (Hand)

Tourniquet Pain
“[HemaClear] Better tolerated… and that routine anesthetic, due to pressure curr discomfort during ankle surgery was avoided."
Clinical Services Journal, Sept 2006. Exsanguinating tourniquet assessed.
“Overall, it was found that in the upper arm, after 10 minutes, the silicone ring tourniquet was associated with a significantly lower pain score than the pneumatic tourniquet.”
Pain and paraesthesia produced by silicone ring and pneumatic tourniquets. JHS(E), 2010
“An experimental study in 20 healthy volunteers concluded that wider cuffs result in more severe changes in the nerve.”
Nerve compression and pain in human volunteers with narrow vs wide tourniquets.
World Journal of Orthopedics, Vol 6, Issue 4, 18May2015
“Significantly fewer patients reported pain in the thigh at the site of the placement of a sterile elastic tourniquet.”
Nondrainage Decreases Blood Transfusion Need and Infection Rate in Bilateral Total Knee Arthroplasty.
Journal of Arthroplasty, 2013. Demirkale, et al
"...produced a highly significant elevation of the pain score by 88.5% (P<0.001) compared to the initial pain score. SRT [HemaClear] was 26.5%. ...
nerve conduction studies showed that wider cuffs result in more severe nerve changes than narrow cuffs"
Silicone ring tourniquet versus pneumatic cuff tourniquet in carpal tunnel release: a randomized comparative study.
J Orthopaed Traumatol. 30Jan2013.
“On the other hand, human volunteer studies have shown that wider tourniquets resulted in more pain and were tolerated for less time than narrow cuffs. "
Silicone ring versus pneumatic cuff tourniquet: a comparative quantitative study in healthy individuals
Arch Orthop Trauma Surg, 29June2010.
“In the narrow HC tourniquet, the isobars from either side overlap, causing less pressure in the central, deep section where compression of the artery and nerve takes place. Skin pressure may be high, but the delicate neurovascular structures are subjected to lesser pressure, and over a shorter distance, with theoretically less damage potential.”
Upper Extremity Nerve Function and Pain in Human Volunteers with Narrow versus Wide Tourniquets.
Journal of Long-Term Effects of Medical Implants, 26(2): 173-181, 2016. Kovar et al.

Many of the fake CAT Tourniquets appear legitimate and could pass a casual inspection. But they are not reliable due to the quality of materials used and the methods of production and assembly. Counterfeit tourniquets are known to fail — the windlass may break off in your hand or bend so that it cannot be secured, the buckle may fail, and internal stitching can come apart. If the tourniquet fails, severe bleeding will resume, endangering the injured person and decreasing their chance of survival.