Flip-open covers are completely weatherproof and keep rain, snow and dust off your expensive optics. The Flip-open system includes an ocular cover with a red button and an objective cover (sold separately) with push tabs. These covers open in an instant with the push of your thumbs, they spring up and out of the way quickly and dependably. Select your covers by measuring the outside diameter of the two scope bells. Then take that measurement and reference the cover measurement listing. Select the cover that is the closest to the measurement with .01 under size and .025 over the size range. Includes ocular (eye piece) cover only. Objective cover sold separately.