Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 501-300-2040 found under Duct Assembly Air C by Senior Operations Llc. The National Stock Number assigned to this part is 1660014332109, and the Federal Supply Class is 1660 Aircraft Air Conditioning Heating And Pressurizing Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 501-300-2040.