Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number N507-3 found under Valve Flow Control by Ldi Industries Inc. The National Stock Number assigned to this part is 4820012191737, 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 N507-3.