Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number DS1221-2 found under Liner Main by Allied Marine Services Inc. The National Stock Number assigned to this part is 4820004279356, 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 DS1221-2.