Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number YCM70821 AND YCA74138 found under Valve Butterfly by Leslie Controls Inc. The National Stock Number assigned to this part is 4820014225170, and the Federal Supply Class is 4820 Valves Nonpowered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like YCM70821 AND YCA74138.