Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number WVTB-ISOLEX DN-0300 ITEM 5 found under Seat Valve by World Valve B V. The National Stock Number assigned to this part is 4820170567254, and the Federal Supply Class is 4820 Valves Nonpowered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like WVTB-ISOLEX DN-0300 ITEM 5.