SPERZEL (Sperzel) Trim-Lok 3x3 Locking Guitar Tuners The Trim-Lok 3x3 Locking Guitar Tuners are a world-renowned standard for locking tuners. Easily lock and release strings by turning the dial on the back of the tuner. Achieves quick tuning and string changes. Also, there's no need to wind the strings multiple times around the tuning post, preventing unnecessary string slack and friction. This also improves tuning stability. *Operation checked, cleaned, and in perfect working order. --------------------------------------------------- Thank you very much for viewing this product! Please feel free to comment if you have any questions. Details and accessories are listed in the images or description. (If you are negotiating the price, please provide your desired price.)