Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number NWHOISB-5490E4XX found under Heater Fluid Electric by Chromalox Corp. The National Stock Number assigned to this part is 4520015367143, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like NWHOISB-5490E4XX.