Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 620-229-4X found under Amplifier Audio Fre by Ametek Programmable Power Inc. The National Stock Number assigned to this part is 5996013051728, 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 620-229-4X.