※ Information regarding price negotiations is included in my profile. Please take a moment to review it beforehand. This is a custom part designed to modify a standard rotary tenor trombone, with the aim of enhancing its sound and resonance. This is the small size. We received feedback that the change in playing feel was quite noticeable when used, so to reduce this, the outer diameter has been made slightly smaller. While the effect is somewhat reduced, the change in playing feel should also be less noticeable. To use, simply remove the rotary cap, insert this part into the inner cap, and then close the cap. It can be easily attached and detached. This is made of cupronickel (nickel silver), aiming for a brighter sound and improved response. The diameter is approximately 19mm, and the hole is approximately 10mm. The thickness is approximately 0.3mm. It should fit most standard rotary valves. (Please note that this is handmade, so there may be some variations and it is not perfectly circular.) While designed for use with trombones, it may also be used with other rotary valve instruments such as tubas and horns, if it fits. (We have confirmed sound changes on trombones, French horns, tubas, rotary trumpets, and German-style tenor horns.) I believe it is possible to make some kind of change to an instrument, but it depends on the compatibility with the instrument and the player, and the desired effect may not be achieved, or a completely different effect may occur. Please be aware that a positive effect is not guaranteed. Also, this is being sold elsewhere. We will prioritize the first person to purchase, so please understand. ps Please inquire if you wish to purchase multiple items. You can get a discount of 150 yen for each additional item, up to a maximum of 6 items. ※ The instrument used in the example of installation is a V.Bach 42B. #FK Tone Disc Search terms: Trumpet Euphonium Tuba Bass