Check the listing for details. Schaller S-Locks Strap Lock System in Black Chrome. Condition: New. Listed at 32.99 USD. Schaller S-Locks Strap Lock System in Black Chrome With their unique design and simple functionality, Schaller's S-Locks strap locks will secure and protect a strap to your beloved instrument. The locks features a Lock-Wheel, one-piece hardened steel strap buttons, and are even in the shape of an S. Overview: Strap Button -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 -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