Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number E21-1 found under Mounting Base Elect by Curtis Straus Llc. The National Stock Number assigned to this part is 5975003559219, and the Federal Supply Class is 5975 Electrical Hardware And Supplies. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like E21-1.