This unit primarily stabilizes tuning by temporarily fixing floating tremolos. 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. It allows you to set a floating tremolo to down-only or hardtail mode, making it easy to change to Drop D tuning. It offers a different approach compared to ESP or Ibanez arming adjusters. We take the utmost care in recording the condition of the item during listing and shipping. Due to the prevention of fraud and item substitution, we generally do not accept returns or claims. Thank you for your understanding. Please feel free to ask any questions before purchasing.