electronic ballast for 2D lamp 1.flame retardant PC casing 2.no flashing,no noise. 3.preheat start function electronic ballast for 2D lamp1.flame retardant PC casing2.no flashing,no noise.3.preheat start function modellampdim in mmhole spacing in mmOG-E38(H)2D 38W114*90*3295OG-E21(H)2D 21W88*68*3270