Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number STK-271-4 found under Valve Bleeder Hydra by Lewis Corp. The National Stock Number assigned to this part is 4820011649310, 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 STK-271-4.