Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number CL503 found under Resistor Variable Nonwire Wound by Reon Resistor Corp. The National Stock Number assigned to this part is 5905001585310, 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 CL503.