Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 31-B570 found under Cover Waveguide Flange by Microflect Co Inc. The National Stock Number assigned to this part is 5985015448110, 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 31-B570.