Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 40421A found under Resistor Variable Nonwire Wound by Sensor Systems Inc. The National Stock Number assigned to this part is 5905006553628, and the Federal Supply Class is 5905 Resistors. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 40421A.