BIAL 10-180X90 Zoom Binoculars Waterproof Super High-Powered HD Binoculars Telescope Diopter adjustment for fine focusing. Rubber-coated body for firm, non-slip grip. Specification: 10-180X90 (marked). Fully coated optics for improved clarity and light transmission Focus: Center the handwheel adjustment and right eyepiece parallax adjustable.