George Wood Handcuffs

This very, VERY rare design is the Wood Chain Handcuffs, based on US patent number 1,056,079 , which was issued to George Alvin Wood in 1913

This pair sold for $736 after 8 bids. 

There are two "lock collars" which allow the chain to pass through until the locking bolt is pressed down to engage with the chain. It was designed to be very lightweight and easily carried. 

The key is unique in that it doesn't have a bit. It's sort of an early tubular key.