Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number MS42S3D found under Attenuator Variable by Herley Industries Inc. The National Stock Number assigned to this part is 5985010689550, 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 MS42S3D.