This DISCOUNTED product is only available in conjunction with the purchase of another PrestoValves product of any size. One discounted Valve Casing Brush per retail bottle purchase. Use a valve casing brush with PrestoValves Formula HLF solution in order to thoroughly clean the casing internally. This is as important as cleaning the piston or rotor. Designed for brass instruments with valves, this valve casing brush features non-abrasive nylon bristles that prevent scratches and keep your valves clean.