Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number BT-4017 found under Transformer Power by P A Electronics Corp. The National Stock Number assigned to this part is 5950016495066, 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 BT-4017.