This is one of the Watch Chains for your vest pocket. Really popular in the early 1900's You would hook the hook on the chain on the top of vest pocket and then put the watch on the swivel and slip it in your vest pocket and when you wanted to see the time. You would pull on the chain and bring it up from your pocket. That way you would not lose your watch as long as you had it on the chain. The really important men had the chains even crossing the vest. For you from Kansas!