Digital Absolute + Axis Goniometer (Built In) Beiersdorf Gauze Distance Spot Ratio: 12:1 Impotence Distance Spot Ratio: 12:1 5v AutoStep© Coaxial Ophthalmoscope Head Only * The Welch Allyn AutoStep© Coaxial Ophthalmoscope uses a Halogen HPX lamp that provides 30% more light output for true tissue color and consistent long lasting illumination * Its 68 lenses in one diopter steps provide better resolution * The integral absolute vertical and horizontal levels are permanently incorporated into the digital goniometer arm * Goniometer reads 0 180 degrees on LCD screen * Has ability to freeze angle measurement * Powered by 1 9V battery * Goniometer exterior is powder coated steel with inch cm marks screened onto arms * Digital angle reached in center * Horizontal and vertical levels to indicate level or plumb starting point *