Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4-4023 found under Level Cylindrical Circular Vial by Geier And Bluhm Inc. The National Stock Number assigned to this part is 5210012264187, and the Federal Supply Class is 5210 Measuring Tools Craftsmens. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 4-4023.