David Whites Levels are known for there accuracy and durability. This comes with a 20 X magnifications optical series of lens. The front has a built in sunshade cover. Accuracy is +/- 1/4" @ 100'. The max range is @ 200' and the minimum is @ 4'. The aperture is 0.75 inches. The level is top mounted for easy viewing. Field of view is 2' at 100'. Horizontal lock and tangent screw for precise movement. This unit is used for measuring vertical and horizontal angles. Made primarily for light construction and surveying projects. This unit is very clean and comes with the original case. No instructions available.