This care cloth was created to clean slides, valves, and tenons on any of the brass family of musical instruments. It is also appropriate wherever there are metal friction connections in a woodwind instrument. The Blitz Slide and valve care cloth provides effective cleaning, extends time between cleanings, and helps make valve oil more effective by reducing tarnish build up. Ingredients are non-toxic. Take apart the valve or slide, rub the metal parts briskly until all tarnish and accumulated dirt has been removed. Wipe the part thoroughly with a clean, dry cloth before reapplying valve oil or slide grease. This cloth will not dry out, but we suggest you store it in the pouch in which it comes, or a polybag. 100% cotton flannel cloth. Non-toxic. Environmentally responsible. Not tested on animals. 4 Pack.