The Geovid HD-R 2700 models, combine ergonomic design and razor-sharp, high-contrast images, along with reliable rangefinding technology. Easy, intuitive operation is guaranteed: equivalent horizontal range (EHR) output requires no pre-programming. In mountainous terrain, EHR gives you greater safety and flexibility. Leica's own algorithm takes into account not only the linear distance and angle but also a realistic ballistic trajectory, making it much more accurate than the cosine function known as the Rifleman's Rule. The result is a highly precise calculation of the EHR at a ballistic function range of 1,200?yds/1,100?m.