The Dunlop Straplok System is the strap retainer designed with the artist in mind. It's 360 degree groove and ball design allows the unit to rotate without catching. Case-hardened steel skin guarantees long life. Inter-changeable strap buttons allow the same strap to be used with several guitars. release-tested up to 800 lbs of pull. Dunlop Straplok buttons will not come loose under normal playing conditions.