Martin Seibold TSE 9 Tone Stability Enhancer for rotary valve Tenor Horn and baryton, improves response and accuracy, makes the sound more centered, instructions: completely unscrew the knurled screw from the TSE, place the threaded part on the valve sleeve from behind and screw both parts together using the knurled screw so that the TSE rests against both valve sleeves, silver plated, made in Bavaria