... Monocular Telescope 1)Model:15-55x21 2)Objective lens aperture:21mm 3)Caliber:21mm 4)View field:2-0.9 degree Compact ... , it will give you a wonderful world....Features:* Mini shape, compact design* Suitable for Golf, Scope, Camping, Hiking, Fishing, Birdwatching, ... *User manualPackage dimensions:130*50*45mm (approx.)Package weight: 113g Compact Pocket-Sized 15-55x Mini Zoomable Monocular Telescope