Zoom Binoculars for Adults High Powered,10-24x50 HD Professional/Waterproof Binoculars ，Durable & Clear BAK4 Prism FMC Lens Binoculars for Birds Watching Hunting Traveling Concerts

Professional Waterproof HD 10-24x50 Zoom Binoculars With Clear Weak Light Vision Durable FMC BAK4 Prism Binoculars, with adjustable eye widths fit most adults and kids. Adjustable eye-cups twists up and down for perfect viewing with or without eyeglasses. Great 10-24x50 zoom binoculars for adults,can be used as binoculars for bird watching and outdoor activities, such as climbing,hiking,hunting,concert, football games, watching wildlife and scenery. Take it home and capture beauty of the world with your parent,friends and children. The adjustment method of back focus is as follows: 1. Take an image with different details (preferably a special test card), the object distance is 3 meters to 5 meters, adjust the aperture to a suitable position, so that a clear image can be obtained on the viewfinder. 2. At the longest focal length, use the focusing ring to adjust the image to the best sharpness. Adjust the back focus ring under the shortest focal length to make the image sharpness the best. When adjusting the back focus ring, loosen the locking screw before turning the back focus ring. Spec: Magnification: 20X-24X Objective Lens Diameter: 50mm Eyepiece Diameter: 20mm Field Of View: 78.8M-45.4M/1000M Prism: BAK4 Optical Coating: FMC Multi-Layer Broadband Green Film (Bright and Sharp Image) Material: Binoculars (Metal) + Anti-slip & Moisture-Proof Rubber Package Includes: 1X Binoculars 1X Carring Case 1X Eyepiece Cover & Objective Lens Cover 1X Lens Cloth 1X Neck Strap 1X User Manual