This is a Paramount PMRHSFMSKL Hot Shoe to Male Screw-Lock PC Sync Cord. It is a 10" long, straight, non TTL cord with a screw-lock PC tip for cameras or flashes that are equipped with a screw-lock PC terminal.
Possible scenarios for use are:
If your camera has no hot shoe.
You wish to fire a second standard hot shoe flash from your camera's PC sync terminal.
You wish to fire a Pocket Wizard Slave and your on-camera flash has no sync terminal.
Note:Sony/Minolta flashes cannot use this item without an additional shoe adapter