S-Locks: S for Safe, Silent & Schaller strap locks In the development of the new revolutionary S-Locks Schaller have combined 3 parts to perfection: unique one-piece hardened steel strap buttons S-Locks suitable for different belt thickness with ergonomic operation and a patented locking nut - Lock-Wheel - with triple security architecture. The S-Locks new strap button��� new and unique one-piece construction, easy to install via 3 mm (1/8"") Allen key. special�4 mm�wood thread in�S-Lock size M�for maximum grip. Different length strap buttons available as an optional extra in sizes S (3.5 mm) and L (4.5 mm). Please refer to the installation instructions on Schaller's website for size specifications. hardest steel for maximum wear resistance and safety including high-grade felt washers to protect your instrument The S-Locks improved new lock extended thread length for holding straps of up to 6 mm thickness, newly designed slanted locking bolt made of stainless steel for minimum wear and thus maximum safety new design pull-up ball for best haptics suitable for a standard hole in the belt of 10 mm The new Lock-Wheel: featuring 3-stage safety concept Lock-Wheel with special patent thread ensures a secure hold. It can be tightened safely by hand without tools. The 2-hole mount (suitable for 2 mm Allen key or screwdriver) allows a firmer tightening torque of the Lock-Wheel with maximum hold. Undetachable hold due to grub screw with tapered cap and slot 2.5 x 5 mm made of stainless steel. Simply unscrew the set screw again to unscrew the Lock-Wheel; the thread remains functional and cuts itself ""free"" again through the Lock-Wheel. Finally... Put all parts together and give it a shake Sounds of silence - You will be amazed: Whether on stage or in the studio, S-Locks do not rattle. Compatibility Schaller Security Locks and S-Locks a.) S-Locks are compatible with all existing Schaller Security Locks like this: strap button old SecLock + lock new S-Lock (without silent feature!) strap button new S-Lock + lock old SecLock only limited, we do not recommend itU Use Schaller's new S-Lock lock with Lock-Wheel on your strap, then you will always be compatible with all strap buttons and at the same time you will always use all the advantages of our new Lock-Wheel.�Please always make sure that the lock is engaged in the strap button, the lock is attached to the belt in such a way that the strap button is secured in the U-shape of the lock and that the instrument does not rotate. b.) One strap for several instruments Choose from more matching strap buttons in different lengths here:   L = male thread 4.5 mm, inside 3.2 mm length 27 mm M = male thread 4.0 mm, inside 3.0 mm; length 22 mm (standard) S = male thread 3.5 mm, inside 2.4 mm; length 18 mm