1. Trumpet mouthpiece decompression valve for corrective blowing, ideal for beginner practice and tone improvement. 2. Professional breath control tool with adjustable pressure settings. 3. Gold-plated brass trumpet mouthpiece with pressure-reducing valve, designed for optimal air density. Features an adjustable spring to support precise lip muscle movement and endurance training. 4. Suitable for beginners, with adjustable spring tension. The pressure-reducing valve helps regulate lip pressure during blowing, encouraging proper vibration for a natural sound and enhanced tone quality. 5. Offers precision and sensitivity, reducing mouthpiece pressure. As pressure increases, the spring compresses smoothly, eliminating harsh or airy sounds. Produces clear tone only when played with relaxed technique. Color: Gold Material: Metal Size: 8.1 x 2.8 cm Package Contents: 1 x Professional Correction Assistant Tool Note: The package includes only the items listed above. Other accessories are not included. Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error is +/- 1-3 cm.