Beileshi 10X50 396FT/1000YDS Sports Military Optics Binoculars Telescope Spotting Scope with Compass for Hunting Camping Hiking Traveling Cocert Wate **Feature**: Waterproof, dust-proof, all-weather binoculars suitable for outdoor use even under severe conditions such as watersports and mountaineering. **How to read the rangefinder scale**: To accurately use the rangefinder scale , you will need to know either the size or distance of the object . When the size of the object is known, the rangefinder scale tells you distance to it . When the distance to the object is known , the rangefinder scale tells you its size. **How to Focusing** : 1. Set right and left eyepiece to zero and sight on a distant object.ed to your eye-strenth, Note diopter setting for future reference. 2. Cover right objective (front )lens with your hand, then rotate central focusing wheel until the image in the left eyepiece is sharp, Keep both eyes open while making this adjustment. Cover left objective (front )lens with your hand then rotate the right eye-piece until the image is sharp again. Image should now be focused to your eye-strenth, Note diopter setting for future reference. **Compass**:You can read your compass in the dark by pressing the compass light swith and illuminating it in red light. If the light becomes faint, change the light battery (LR43*2, Alkaline batteries ). Using a coin , unscrew the cover of the battery compartment and change the battery , making sure the new one is inserted correctly .