Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 81K1 found under Transformer Power by The Grieve Corporation. The National Stock Number assigned to this part is 5950008671309, 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 81K1.