Product is composed of a glass shell, a baffle, a fluorescent plate, field electrode, a cathode, an anode and the base, the diameter of the main pipe is not less than 40 mm and the length is not less than 270mm, The electrode distance is not less than 219mm, the length of the fluorescent board is not less than 120mm, the width is not less than 35mm, and the fluorescent plate and the glass tube axis are about 10 degree.The baffle slot width of 0.8 ~ 1mm. Tube vacuum range of 0.13 PA (1 x 10-3 torr) ~ 0.07 PA (5 x 10-4 torr), the cathode ray tube electrode is made of pure aluminum with no less than 99.7%.