Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 3TX7131-4DC03 found under Battery Power Source by Optima Batteries Inc. The National Stock Number assigned to this part is 6130016942857, and the Federal Supply Class is 6130 Converters Electrical Non Rotating. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 3TX7131-4DC03.