Specification: Product Name: 25-75x60 Zoom Telescope Multiples: 25-75x Eyepiece diameter21mm Field of view2..1-1.08 Prism systemBaK4 all-optical prism Objective lens diameter: 60mm Exit pupil diameter: 2.4-0.8mm Distance:3m Prism: BAK4 Prism type: porro Coating: FMC Multi-layer coating Waterproof: yes Anti-fog: yes Shockproof: yes Features: Focusing with one hand HD, high transmittance Support mobile-phone shooting Application: Boating / Yaching, sports, bird watching, auto racing, horse racing, hunting, beach, travel Core Benefits 60mm large objective lens 25x-75x zoom Attachable mount Multi-layer coating 60mm large objective lens The larger the caliber the higher the light intake The brighter the image High Image Clarity And Reproduction In general, the larger the aperture of the telescope, the better, in the light and dark contrast, such as dusk and morning, the larger the aperture of the higher the amount of light into the telescope, the brighter the image of the telescope, the eye can see more details Infinitely variable magnification Easy adjustment 25-75x infinitely variable magnification design Adjustable in the middle at any magnification BAK4 Prism FMC Multi-layer Broadband Coating