Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number A1N216 found under Ring Piston by Mks Instruments Inc. The National Stock Number assigned to this part is 2805009860533, and the Federal Supply Class is 2805 Gasoline Reciprocating Engines Except Aircraft And Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like A1N216.