Russian Side-Key Handcuffs

While these look like typical swing through handcuffs, they use a gear locking system rather than a pawl. The keyhole is on the base of the cuff lock case (near the swivel.) The key is screwed in and pulled to disengage the gear, unlocking the handcuffs. They don't have a double lock. The locking mechanism is similar to the Takeda Handcuffs. They are thought to be of Russian manufacture.