Patented new Axial PointScource™ Optics. Illumination system converges the light to a point at the cornea, allowing easy entry into small, undilated pupils. The illumination pathway then diverges to the retina, illuminating a very wide area of the fundus. Viewing system enables the operator to view the illuminated area on virtually the same axis, creating the widest field-of-view attainable. Provides a five-times larger view of the fundus than every before achieved with a standard ophthalmoscope in an undilated eye. Increases magnification by 26% over a standard ophthalmoscope. Patented Glare Extinguishment System prevents interference from unwanted glare and reflections. Works with all existing Welch Allyn 3.5v power sources (battery handle or wall transformer) saving additional investment. The patient eyecup establishes and maintains proper viewing distance, provides stabilization for the view, is a pivoting point for leverage in panning around the retina, occludes ambient light, and helps with orientation. The dynamic focusing wheel adjusts the focus in a continuous, smooth action for more precise control and the optimum view with a focusing range of -20 to +20 diopters. The aperture dial has micro, small, and large spot sizes, a slit aperture, and red-free filter, and cobalt blue filter with add-on corneal magnifying lens (Model 11820 only). The handle with power source and bulb are not included. Please indicate if you would like this in addition to your order.