MARATHON BI030002 Compact Roof Prism 8x21 Military Grade Binocular. Compact for sports, safaris, tracking, mountaineering, bird watching and other outdoor activities PRISM- BK-7 Roof prism. 8x magnification and 21mm objective lens diameter. GLASS COATED LENSE- Provides superior image brightness. FIELD OF VIEW- 365ft @ 1000 yds / 126m @ 1000m. FOCUSING- Center focus with independent right ocular adjustment. ACCESSORIES INCLUDED- Neck strap, carrying case, lens cloth and instructions.