This replacement bulb has become the new standard on virtually all Whelen halogen lighting products. The snap-in base allows for easy replacement of these bulbs. This 20 Watt version also known as Red Dot is compatable with 508 Series, 64 Series, 810 Series, 830 Scenelight, AdvantEdge+Plus & Super AdvantEdge+Plus Lightbars, Towman's Lightbars, Edge+Plus, B-Link Bar Full size Halogen Modules, Dash-Miser Halogen Models.