Features: 1.Every product has a unique Manufacturing Part Number label on the inner package that proves it has been qualified,which include Part Number,Model Number and inspection date information; 2.If you have any questions about the item,please provide us the Manufacturing Part Number for checking,your profits will be guaranteed. 3.Unique cork pads to prevent scratching the instrument. 4.Crafted from aluminum, for a brighter tone. 5.A good partner for your trumpet. Specifications: Material: Aluminum Color: Silver Brand name: Unbranded Size: 9.5x6.1x3.2cm/3.7x2.40x1.26inch(HxBigger Dia x Smaller Dia) Cork interface diameter: about 33mm/1.3inch .