This is for a locknut,... NOT a stringlock. Locknuts and stringlocks are two different types of locking devices that do almost the same thing. It goes like this.... locknuts always sit at the end of the fretboard and incorporate the nut (the slotted part on the neck where the string vibration stops). It's both a lock, and a nut... it's a locknut. Stringlocks are slighlty different because they are attached to the headstock downhill from the nut and is just the "locking" portion. In other words, they only lock the strings so it's simply called a stringlock. This stringlock clamp plate has a hole with threads that accept the stringlock clamp screws.