Special Price! Request Listing TMS Kobo Original Sound Improvement Goods Rotary Spacer-kun (Copper Hammered and Heat-Treated) This sound improvement device is designed to be placed between the rotary caps of a French horn. It changes the sound's responsiveness and resonance. It offers the rich resonance of copper and the improved attack due to hammering. Furthermore, heat treatment enhances the sound. Compatible with Alexander horns 1-3. May also be compatible with others. Outer diameter: 22mm, Thickness: 1.5mm, Hole diameter: 10.5mm Made of copper