Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 8171E1-4HS2 found under Valve Rotary Selector by Teledyne Technologies Inc. The National Stock Number assigned to this part is 4820000010010, 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 8171E1-4HS2.