Atlas Optics Sky King 10x42 Binocular Fully Multi-coated Lenses / Roof Prisms /Magnesium Alloy Body /Rubber Armoring /Multi-position Eyecups /Center Focus Wheel Waterproof & Fogproof /Barrels are filled with argon gas to inhibit internal fogging. BaK-4 Prisms Optimize light transmission/Dielectric Prism Coatings Covered by Vortex Optics VIP Lifetime Warranty