Product Features •360 degree clear acrylic base admits light from all directions •Comes with measuring reticle, carrying case and lens cleaning cloth •Smooth helicoid twist focus mechanism •Focuses from +2 to -2 diopters to give you a sharp image •0.8"lens diameter •1.1" field of view •4 lens optical system •.005" scale division with 35mm scale diameter 0.8" measuring range •1.81" diameter x 1.73" height (46 x 44mm)