ADI MK IV SAF-LOK handcuffs

This is an extra high security swing through ratcheting modern handcuff from Australia. It uses a "paracentric" tumbler lock, and has keyless double locking capability. $199 starting bid with one original key. 

Close up detail of brand stamps. ADI is Australian Defense Industries. The MK5 is their high security hinged handcuff. The MK 1 was a prior chained model. 

These handcuffs have integrated swivels and three stout round links.