AP-0681 Schaller 445 S-Lock System

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 3mm/ 1/8").
4 mm/ 5/32“ screw with self-tapping wood thread for maximum hold in wood for almost all instruments with existing screws in standard dimensions; for all other cases we offer strap buttons in XL and S format (see below); in any case, please read our installation instructions below carefully;
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.
suitable for a standard hole in the strap of 10mm
  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 M2,5x5mm to attach it permanently.