These are a pair of sling mounts for Picatinny rails, one has a rail on it if you're into that sort of thing. You'll need to print out the mount and go to the hardware store, in search of an eye bolt that can thread into one of the four holes on the rounded end, and one long screw that can fit into the rail locking hole. I have no idea what size screws will work, but I'm sure there's a wide variety.