Perimeter By G. T. Scientific Industry

We offer Perimeter. Automatically records field to 90 degree in all meridians. The crier mechanism is smooth, silent and invisible. The patient perceives only the test object to move. Spring check, giving an audible click to each 15A of rotation of the arc in either direction renders close scrutiny of dial plate unnecessary, and ensures accurate registration. The device can be thrown out of action if silent movement is desired. The marker a needle is housed in a retractable tube, sprung to sheath the pint when actually marking. A set of interchangeable and permanent washable test objects is included with the instrument. The objects subtend angles of 4A , 1A , A , A A and are in white, green, and red blue object in the last three sizes are also included. Supplies complete with transformer to work on 220 volt A/C mains with 100 charts.