Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4E309 found under Tape Insulation Electrical by Grainger Div Of W W Grainger Inc. The National Stock Number assigned to this part is 5970015864391, and the Federal Supply Class is 5970 Electrical Insulators And Insulating Materials. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 4E309.