Schaller's strap lock system, S-Locks, offers quiet operation, a one-piece hardened steel strap button, decorative design, complete maneuverability, and a beautifully elegant locking wheel that provides a very smooth action. It is installed on the guitar body using a 3mm hex wrench. - Uses 4mm / 5/32 self-tapping screws. - Made of hardened steel and is twice as thick as regular strap buttons, boasting the highest durability. - The included high-quality felt washers protect the guitar's finish from scratches caused by interference with the strap buttons. Strap Lock The new pull-up ball design allows for easy locking or release. - The threaded length is extended, allowing it to be secured to straps that are 6mm or thicker. - The slanted stainless steel locking bolt reduces finish wear. Installation in 3 steps - Turn the locking wheel with the threads. - Tighten the locking wheel using a 2mm or 5/64 hex wrench or screwdriver. - Finally, secure with the set screw. - Model Name: S-Locks M Gold - Color: Gold - Condition: Opened, unused *I am selling this because the screw diameter did not fit my guitar.