Gehmann 590-B Lightweight Biathlon Rear Sight.  New rear sight in use by many on the World Cup.  Extra large adjustment knobs for ease of use with gloved hands, snow cover with adjustable-position handle.  Does not include rear diopter but will accept all Anschutz and Gehmann rear diopters threaded M9.5x1.0mm.  Several options available elsewhere on our site.  Gehmann 510N for example.