Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number FI21.72AGB 350MM PN21 found under Disk Valve by Naf Ab. The National Stock Number assigned to this part is 4820014284312, 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 FI21.72AGB 350MM PN21.