Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number RV-40 PART NUMBER 21 found under Indicator Liquid Quantity by Golden Arrow Marine Ltd. The National Stock Number assigned to this part is 6680013482504, 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 RV-40 PART NUMBER 21.