Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number S503C553G41 found under Heater Thermal Rele by Westinghouse Electric Corp. The National Stock Number assigned to this part is 5999008244435, and the Federal Supply Class is 5999 Miscellaneous Electrical And Electronic Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like S503C553G41.