Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number BX1931 found under Transformer Audio F by Baltimore Tool Works Inc. The National Stock Number assigned to this part is 5950005776985, and the Federal Supply Class is 5950 Coils And Transformers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like BX1931.