Designed for accurate quick examination of refractive indices and mean dispersion of liquids, solids and power. N.D. Range 1.3000 to 1.700 in steps of 0.001. The body of instrument has learning of 60. It consists of Abbe double prisms with thermostat compen stor Telescope. Mirror, Limb,Graduated Sector Reading Magnifier and radial arm, Complete in wooden box.