From the original inventers of the strap lock, this set of 2 Schaller S-Locks are an updated version of their patented design, used to secure your guitar strap to the guitar body to prevent any chance of them separating during playing. The locking system works by installing a specially designed lock to your guitar strap and corresponding strap buttons to your guitar. The strap can be easily attached and removed from the guitar when required by pulling out the locking bolt, the locking bolt release has been re-designed to be easier to grip and the locking bolt has been bevelled on one side to ensure it easily locks in to place on the buttons. The locking bolt is made from stainless steel for strength and long term durability. The length of the threaded section on the strap piece has been increased to accommodate large straps up to 6 mm in thickness and to accept their new lock wheel. Instead of a nut and washer the lock wheel screws on to secure the strap to the strap lock with no tools required (ensure the rounded wheel edge points outwards), for extra security the wheel can be tightened by inserting an allen/hex wrench through the side holes for extra leverage when tightening (do not overtighten), and finally a set screw in the wheel locks in to the thread to ensure complete security. The strap button and screw have been redesigned too and are now made from one piece of solid hardened steel for extra strength over the old separate screw and strap button design. The button has a 4 mm self-tapping wood screw and is installed with a 3 mm allen/hex wrench. We also stock the Schaller S-Locks buttons on their own as a separate item to install on your other guitars and then you can use one strap with S-Locks installed across all guitars with the locking buttons installed on them.