These new revolutionary S-Locks are silent. They feature one-piece hardened steel strap buttons, aesthetic design, perfect handling, an elegant Lock-Wheel and all former hiccups have been tackled! These new revolutionary S-Locks are silent. They feature one-piece hardened steel strap buttons, aesthetic design, perfect handling, an elegant Lock-Wheel and all former hiccups have been tackled! New silent feature for noiseless performance while moving and playing your instruments. New and unique solid one-piece strap button in hardened steel with self-tapping wood thread. Simply screw it on with an Allen key (size 3 mm/ 1/8"). 4 mm/ 5/32" screw with self-tapping wood thread. Fits all existing strap buttons incl. Gibson for perfect replacement without adjustments on existing holes and screws (XL and S version also available as replacement kit). Hardened steel and more than double thickness of the strap button guarantees maximum security against breakage. Including high-grade felt washers for ultimate protection of guitar's finish. Extended thread length for holding straps of up to 6 mm thickness. New designed slanted locking bolt in stainless steel for permanent precision, reliable performance and wear-free finish. New designed pull-up ball for easy-grip lock and release. New Lock-Wheel with unique blocking features. Schaller`s S-Locks are fully compatible with all existing Schaller Security Locks.