3 pieces = 1 S-Lock. Perfect! Strap button 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). 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. 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. Lock 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. Lock-Wheel New Lock-Wheel with unique 3-Step security function: Screw our lock wheel with patented self-locking thread tool-free by hand, you already protect your guitar sufficiently (the round shaping must be facing the pull-up ball!). Use a 2 mm or 5/64’’ Allen key or screwdriver to tighten it for maximum security. Use our micro cone-top screw to attach it permanently. All S-Locks come in a new and attractive re-usable crystal box. Two more things… S-Locks are fully compatible with all existing Schaller Security Locks! Only one strap and one pair of S-Locks for all your guitars!