Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 73R5554 found under by Kool Radiator Service Inc. The National Stock Number assigned to this part is 6150015821982, and the Federal Supply Class is 6150 Miscellaneous Electric Power And Distribution Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 73R5554.