Key Features Magnetic Rechargeable - Convenient and there is no necessary to take off the green beam, without any removal or re-zeroing.Highly Visible Green Beam - the output of the green beam is less than 5mW, Class IIIA. The beam distance is about 100 meters/ day; 1500 meters/ night. Durable and Shockproof Aluminum Design - It is good at holding up to being knocked around a good bit and Keeping zero. Low Profile Design is Compatible with M-Lok Rail - You can attach the sight to Rifle Rail directly. One rubber button for rifle Beam on/off. Easy Zero Adjustment - Slowly tune Elevation and Windage interactively with included Allen key. Noted, only one direction may lock or damage the threads. (Elevation Max: 2 target circles; Windage Max: 1.5 target circles)