Description: 100% Brand New Ideal for shotguns, pistols, black powders and crossbows High quality aluminum alloy in resistant black matte finish 5 brightness levels in Dual illuminated reticle(red and green) Wide field of view and unlimited eye relief Lightweight, dust-poof, weatherproof, and shockproof 5 M.O.A Dot Red & Green dot Compatible for 11mm & 20mm Weaver Rail Specifications: Magnification: 1X Objective diameter: 40mm Exit pupil: 28mm Tube diameter: 38mm Field of view: 57° Eye relief: Unlimited Optical coating: Multi coated Illuminate: Red & green Brightness control: 5 levels Color: Black Material: Aluminum alloy. To use this, you hold the camera about 1-1/2 feet from your eyes keeping both eyes open. You hold it so your dominate eye looks through the scope and position the red-dot over the target. With both eyes open, you can see the entire sky so finding your target is easy, just like pointing your finger at it. You can set this up on the top of a telephone pole and used another camera. You can see the dot over the pole and also see in in live view on the LCD.When use these on two other zoom cameras. With practice, you can see something as small as a high flying jet and from picking the camera up, have it in the frame in about 1 second. Using the viewfinder or LCD is much slower and sometimes next to impossible. This sight has an adjustment range of ±30, which is standard. This adjustable range may not be enough for some cameras when used as a finder on camera. It can also be used for hunting or target shooting, which will allow you to take quickly aimed shots at short range while still giving you the ability to make effective shots at medium ranges. And it can also be the finder of the telescope, which will make your telescope easier and more accurate than ever - day or night.