Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number ITS-21-ITS-20 found under by Itt Barton Industrial Sales. The National Stock Number assigned to this part is 5930015482122, and the Federal Supply Class is 5930 Switches. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like ITS-21-ITS-20.