Smaller interpupillary distance adjustments mean anyone from children to adults can enjoy the serious optical performance of the BX-1 Yosemite® Series binoculars. Smooth Focusing Twist Up Eyecups Armor coated, rugged, and waterproof. L-Coat™ BAK4 Prisms Close focus distance of 10 feet. Ergonomic Design Diopter Focus Narrow Interpupillary Distance Porro Prism Design Fully Multi coated Lens System