The Tasco Essentials Roof Prism Binocular are ideal for birding, hiking, travel, or even star gazing. The right-side barrel has an adjustable diopter for easy adjustment as well as a center focus wheel for fast and smooth clarity. Additionally, the Essentials features multi-coated lenses and durable weather resistant housing. Features of the Tasco Essentials Roof Prism Binocular: Adjustable diopter Center focus wheel Multi-coated lenses Tasco Essentials 10x42 Black Roof Binocular ES10X42