Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number K680-9 found under Valve Check by Dynamic Air Engineering Inc. The National Stock Number assigned to this part is 4820014212333, 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 K680-9.