Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 31M 309 1 found under Relay Electromagnetic by Cooper Bussmann Corp. The National Stock Number assigned to this part is 5945016713312, and the Federal Supply Class is 5945 Relays And Solenoids. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 31M 309 1.