Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number AD3977 found under Cooler by Modine Mfg Co. The National Stock Number assigned to this part is 2520006280973, 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 AD3977.