Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 22978-4000 found under Line Radio Frequency Transmissio by Alek Industries Inc. The National Stock Number assigned to this part is 5985012720176, and the Federal Supply Class is 5985 Antennas Waveguides And Related Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 22978-4000.