Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number ELF-3-RV40-4.0IN STK found under Gage Rod Breather Liquid Level by Hydac Corp. The National Stock Number assigned to this part is 6680011499200, 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 ELF-3-RV40-4.0IN STK.