Opticron 8 x 42 Discovery WP PC Roof Prism. Using an ultra-compact optical design, the Discovery WP PC series are among the smallest waterproof roof prism binoculars available on the market today. Standing just 108mm high and weighing 391g - the 8x32 sets a new standard for pocketable full-size binoculars, while the 8x42 and 10x42 at 133mm deliver 42mm