Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 3561 found under Adapter Hoisting by United Technologies Corporation. The National Stock Number assigned to this part is 3940000376874, and the Federal Supply Class is 3940 Blocks Tackle Rigging And Slings. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 3561.