https://www.handcuffwarehouse.com/cts-thompson-handcuffs-model-1008-tri-max-security-handcuffs/
CTS Thompson Handcuffs Model 1008 Tri-Max Security Handcuffs
The internal bar not only strengthens the hold vertically and laterally, but inhibits a shim from entering the nose or the rear of the shackle.
cts thompson handcuffsmodeltrimaxsecurity