This is a YTR-3330. I purchased it used in the past. I have summarized the following points of concern. Repair is required, so it is recommended for those who can repair it and use it. ① The 3rd piston is deteriorated and will not return when pushed in, so the surface needs to be shaved down. The 1st and 2nd pistons move smoothly. ② The main tuning slide is stuck. Other slides move smoothly. ③ The solder is coming off on the brace extending from the main tuning slide to the 3rd trigger and the trigger extending from the main tuning slide to the casing, so soldering is required.