Bushnell H2O Waterproof/Fogproof Compact Roof Prism Binocular Magnification x Objective: 10x 25mm BaK-4 prisms for bright, clear, crisp viewing Multi-coated optics for excellent light transmission 100 percent waterproof - O-ring sealed and nitrogen purged Non-slip rubber armor absorbs shock while providing a firm grip 100% waterproof, O-ring sealed and nitrogen purged for reliable BaK-4 prisms and multi-coated optics offer crisp clear images with improved light transmission Non-slip rubber armor and Soft Texture Grip absorbs shock and provides a firm grip 10x magnification and 25mm objective diameter; 15-foot close focus distance; 12mm eye relief Large center-focus knob for easy adjustments; Twist-up eyecups; Limited lifetime warranty