The Dunlop straplock system is the strap retainer with the artist in mind. 360 degrees groove & ball design allows the unit to rotate without catching. The case hardened steel skin guarantees long life. The same strap can be used with several guitars, as the strap button is interchangeable. Release tested up to 800lbs of pull. It will not come loose. Set (2 units for instrument & strap) adapts to instrument by replacing existing strap pins / screws with special Straplock system buttons / screws. Two strap attachments are included for your strap. Wider flange button provides extra security.