For a complete fastener this item also requires: Loxx key, a Loxx lower part and a 3/8" Punch. LOWER PART W/REGULAR WASHER – NICKEL ON BRASS. Contents: 1 upper part big head with standard washer (clamping range up to 3 mm).
Great product as a guitar strap lock but I really had to struggle to get the strap clamp to grip onto an averagely thick strap, I could barely get one turn on the thread.