Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number VCD-23 10X10IN MS4120F-1204 found under Damper Assy Vent by Greenheck Fan Corp. The National Stock Number assigned to this part is 4140015831101, and the Federal Supply Class is 4140 Fans Air Circulators And Blower Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like VCD-23 10X10IN MS4120F-1204.