Swarovski Optik 58140 10x30 CL Companion Water Proof Compact Roof Prism Binocular with 5.7 Degree Angle of View, Black Fully Multi-coated Lenses: Increase light transmission with multiple anti-reflective coatings on all air-to-glass surfaces Phase Correction: Enhances resolution and contrast through roof prisms BaK-4 Prisms: Optimize light transmission Roof Prisms: Appreciated for a streamlined shape and durability Polycarbonate and Aluminum Body: Is lightweight