The Tasco 10x42 Sierra Full Size Roof Prism binocular is an ideal choice for outdoor activities such as bird watching, hunting, hiking, and more. This Sierra roof prism delivers impressive brightness and increased contrast to produce detailed images, thanks to the Tasco's multi-coated lenses. The binocular is rubber armored to withstand the harshest of environments. Its fogproof, waterproof and shockproof construction allows the binocular to be at home in all weather conditions. Its smooth center focusing knob allows rapid target focus, even when you wear gloves in cold temperatures.