slim type T8 ballast,life about 3 years. steel cover Our high quality Electronic ballast, for T8 Fluorescent lamps, 1X18w, 2X18w, 1x36w, 2 x 36wIt is normal quality, life up to 3 tears, Power facotr:0.95-0.99also have another type for T5, 21w,35w,54wwe can also supply SKD of our ballast