The Microdot, Removable Base, Advanced sight (MD-RB-AD) takes everything we learned from our best selling MD-ADS microdot and refines it a step further. MD-RB-AD features an estimated 50,000 hours of battery life from the included CR2032 battery, powering an ultra-sharp 2 MOA dot. Fully multi-coated lenses and an ultra-low profile emitter ensure a clean sight picture with minimal lens tint. Eleven brightness settings are controlled by the rotary knob on the right side. The first two settings are compatible with night vision units and cannot be seen by the naked eye. The brightest settings are daylight bright. The illumination knob physically stops at "0" with the red dot turned off.Covered by the Primary Arms lifetime warranty, MD-RB-AD is designed for use on heavy recoiling firearms such as shotguns. Constructed of 6061 aluminum throughout, MD-RB-AD features a Type II anodized matte black finish. Waterproofing is improved over previous models-for example, the turr...