Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 11644-20018 found under Shim Waveguide by Keysight Technologies Inc. The National Stock Number assigned to this part is 5985016501800, 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 11644-20018.