RD VD41-332 Green Dot Compact holographic with easy on/off switch on the side. Switch when tapped also increases the intensity of the light. Depress button for 3 seconds to turn on. Depress button for 7 seconds to turn off. 100% waterproof, and can be used with the pistol mounts that we offer. Comes with an extra O-ring seal. Heavy-duty construction and easy installation. Windage and elevation adjustments are easy and can be locked after it is zeroed in.