Lutron NF-10 fluorescent dimmers for use with magnetic ballasts (generally cannot be dimmed effectively below 20 percent). For best preformance and reliablity, Lutron recommends using Hi-lume or Eco-10 dimming ballasts. Single pole, slide-to-off dimmer with wall plate. The original smooth linear slide dimmer. Heavy duty components for surge protection and long product life. Power failure memory.