PCF WP II (Center Focus Porro Water Proof), but the paper has excellent characteristics - besides the apparent field of view of 50 degrees and porro prism binocular is nitrogen filled and waterproof, which ensures longevity. The picture shows an attractive modern design which is indeed functional because of binoculars is in good hands, a rubber body is comfortable to hold at low temperatures. Mechanically, this is the best binoculars I've now had the chance to use.