: Advantages: 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.Clean all valve threads thoroughly.4.Made of copper Gently lubricate the thread. 5.Mount the cap accurately, do not apply extra effort. Sometimes the thread is tight so, proceed slowly.6.this trumpet maintainace tools can replace for fixing and replacing for trumpet lower cover Specifications:Material:CopperColor:GoldenSize:2.2x1.4cm/0.87x0.55inch(Dia x H)Weight:92g Package include:3 x Trumpet Bottom Cap