Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 301-SD-640 found under Boot Power Transmis by Dana Off Highway Products Llc. The National Stock Number assigned to this part is 2520008537165, and the Federal Supply Class is 2520 Vehicular Power Transmission Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 301-SD-640.