Metalarc Powerball ceramic E17, ED17, BT28, BT37, ET18 and ET23.5 high wattage lamps meet today's color critical needs by combining conventional metal halide pulse start characteristics such as good efficacy and long life with improved lamp-to-lamp color consistency and high CRI (R9). Compared to conventional quartz metal halide products, SYLVANIA Powerball ceramic arc tube metal halide lamps exhibit less color variation and higher efficacy. Metalarc Powerball ceramic lamps feature a superior performance, spherical arc tube geometry that maximizes lumen output, lumen maintenance color consistency and lamp life. They operate on existing ANSI specified magnetic ballasts and on compatible electronic ballasts. The lamps can be used in appropriate existing fixtures designed for metal halide lamps of similar wattages and configurations. To maximize energy savings, system performance and system warranty, consider operating these lamps on QUICKTRONIC MH electronic metal halide ballasts.