The Dunlop Straplok System is the strap retainer designed with the artist in mind. Its 360 degree groove and ball design allows the unit to rotate without catching. Case-hardened steel skin guarantees long life. Interchangeable strap buttons allow the same strap to be used with several guitars. Release-tested up to 800lbs of pull, Dunlop Straplok buttons will not come loose under normal playing conditions. Complete installation instructions inside.