Feature rich 2.5v Pocket Ophthalmoscope provides all of the features, none of the bulk. The 5112N series features: 5 aperture selections (small spot, large spot, semicircle, fixed and red-free filter) 19 viewing lenses from -20 to +20 diopters for better resolution Illuminated magnified lens dial Rubber brow rest 2.5v Xenon lamp for true tissue color "AA" battery handle (batteries included) with on/off power switch integrated into pocket clip Choice of fitted hard case or nylon pouch with belt loop Ophthalmoscope in hard case measures 7 1/4” x 4 1/2” x 1 1/2”, weighs .82 lbs. Ophthalmoscope in soft case measures 1 1/4” x 7” x 3 3/4”, weighs .38 lbs. 1 year instrument warranty, lifetime warranty on optics Ophthalmoscope meets or exceeds ISO 10942, ISO 15004-1, and ISO 15004-2