The Dunlop Strap Lock System is the strap retainer designed with the artist in mind. 360 groove and 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 800 lbs. of pull. It will not come loose. Set (2 units for instrument and strap) adapts to instrument by replacing existing strap pins / screws with special Strap Lock System buttons / screws. Two strap attachments are included for your strap.