Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number TIB-728-0394 FIG.21 ITEM 30 found under Seat Valve by Vaf Instruments Bv. The National Stock Number assigned to this part is 4820171097209, 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 TIB-728-0394 FIG.21 ITEM 30.