Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 6BB3900 78 3AA found under Filter Band Pass by Trilithic Inc. The National Stock Number assigned to this part is 5915011508073, 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 6BB3900 78 3AA.