Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number J133B1 found under Bulb Electron Tube by Corning Glass Works. The National Stock Number assigned to this part is 5960010043030, and the Federal Supply Class is 5960 Electron Tubes And Associated Hardware. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like J133B1.