The Welch Allyn 2.5V Pocket Scope Ophthalmoscope uses halogen light for true tissue color and consistent, long-lasting illumination. It is lightweight and compact and 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.