Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number A539 250CL3B4D found under Amplifier Elevation by Westamp Inc. The National Stock Number assigned to this part is 5996001846209, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like A539 250CL3B4D.