Lightweight electronic ballasts, for metal halide lamps, are 50% smaller than industry standard case and weigh 6-9 oz. They are available in Mini-Slim (5.51 x 1.74 x 1.18 in.) and Mini-Square (3.744 x 2.976 x 1.205 in.) styles for 20 and 39 W lamps. Resonance start technology improves lamp starting and hot restrike performance. Lamps maintain consistent color despite voltage fluctuation. Also available is 150 W Multi-Slim (8.287 x 2.58 x 2.17 in. and less than 2 lb), which is suited for recessed downlights.