Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 256500-MBA-42M found under by Cortelco Usa Inc. The National Stock Number assigned to this part is 5805011748869, and the Federal Supply Class is 5805 Telephone And Telegraph Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 256500-MBA-42M.