Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 503-157 found under Cable Assembly Radio Frequency by Nortech Systems Incorporated. The National Stock Number assigned to this part is 5995004924505, and the Federal Supply Class is 5995 Cable Cord And Wire Assemblies Communication Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 503-157.