This unit is primarily used to temporarily fix floating tremolos and stabilize tuning. It's a high-spec tremolo stopper. This is a used item, with the main unit and replacement parts for sale. All parts are genuine and in good working order. While there is some wear, there is no extreme abrasion or damage. The set includes a thumb screw for fixing without a rubber bushing. In recent years, it has become known for being used by Guthrie Govan. It allows you to set a floating tremolo to down-only or hardtail mode, making it easy to change to Drop D tuning. It's a great product with a different approach than ESP or Ibanez arming adjusters. I used it installed on a Gotoh 510 (synchronous tremolo). It can be used with Floyd Rose, Wilkinson, Fender genuine tremolos, etc., if it fits the spring insertion hole of the tremolo block. We take the utmost care when listing and shipping, and handle everything after recording the condition. Basically, we do not accept returns or claims to prevent fraud and item substitution. Please understand. If you have any questions, please feel free to ask before purchasing.