Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 9B1131-1 found under Filter Radio Frequency Interfere by Spectrum Controls Inc. The National Stock Number assigned to this part is 5915014086647, and the Federal Supply Class is 5915 Filters And Networks. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 9B1131-1.