Eyeskey 10X50 Telescope Measurable Large Caliber High Magnification HD Low Light Level Night Vision Waterproof Monocular Binoculars Model:10X50 Structure:single telescope Use:Civil Telescope Instrument magnification:10 times 1. Specifications: Objective lens diameter: 50mm Eyepiece diameter: 22mm Features: large diameter, measurable distance, eyes are not swelled Objective lens coating: all-round multi-layer coating Eyepiece coating: Omnidirectional multi-layer coating Prism material: BAK4 Weight: 396 grams Size: 165x60mm The package includes: 1x telescope 1x objective cover 1x eyepiece cover 1x telescope bag 1x wiping cloth 1x manual ? 2. Nitrogen-filled waterproof design, the mirror body is filled with high-purity nitrogen, waterproof and mildewproof, improve service life and durability. 3. Using FMC coating, multi-layer coating treatment is applied to all mirrors to effectively enhance light transmittance, clear and bright image, and higher color saturation. 4. Eyepiece diameter is 50mm, the amount of light is the most abundant, the image is the clearest, the farthest is seen, it helps to relieve eye fatigue, and the viewing is more comfortable. It is often used to watch concerts, sports events, animal migration, etc. 5. The prism is made of BAK4 material, which enhances the refractive index and has high light transmittance, effectively avoiding vignetting.