Model 12820 is a 2.5V Pocket Scope Ophthalmoscope. This lightweight and compact ophthalmoscope uses halogen light for true tissue color and consistent, long-lasting illumination. It comes with an AA-battery handle and two AA Alkaline batteries. The ophthalmoscope has five aperture selections for general and specialist use. 48 lenses for better resolution. Its polarized filter reduces corneal reflection. Plus, 12 aperture/filter combinations for greater versatility: micro, small, and large spot sizes, cobalt blue filter for corneal exams, fixation target, and slit aperture, plus red-free filter and unfiltered halogen.