Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number S543-12 found under Ring Piston by Tyco Valves And Controls Lp. The National Stock Number assigned to this part is 2825005552126, and the Federal Supply Class is 2825 Steam Turbines And Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like S543-12.