Antibiotic zone reader offers antibiotic zone reader, most suitable to measure the diameter of the inhibited zone in microbiology, botany, zoology, bacteriology and pathology labs. The instrument is unique in design and measures the diameter of the inhibited zone to 0. 1 mm within the range of 0 to 35 mm. Light from a source in the base passes up through the transparent and semitransparent portion of the agar-agar, then to a reflecting mirror supported by an arm above the unit. The mirror reflects the light to a glass prism mounted at the front of the unit and the magnified image of the zone of inhibitions can be clearly seen on the prism. The instrument is supplies complete with all the required accessories like prism, petri dish, etc. The unit is suitable for operation on 230 v, 50 hz, single phase ac supply.