Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 81223-0063 found under Valve Check by Ling Electronics Ltd. The National Stock Number assigned to this part is 4820012909052, 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 81223-0063.