Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 503 0003 01 found under Ring Hysteresis by Allen R C Instruments Inc. The National Stock Number assigned to this part is 5365003159289, and the Federal Supply Class is 5365 Bushings Rings Shims And Spacers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 503 0003 01.