This portable set features Welch Allyn's finest diagnostic instruments. The Coaxial Ophthalmoscope (11720) uses a Halogen HPX lamp that provides 30% more light output for true tissue color and consistent, long-lasting illumination. It has 28 lenses from -25 to diopters for better resolution. The coaxial optical system produces a shadow-free spot and easier entry into undilated pupils. The crossed-linear polarizing filter reduces corneal reflection. The red-free filter may be used with any aperture. It has 18 possible aperture combinations for greater versatility. The Welch Allyn 3.5v Pneumatic Otoscope (20200) uses a Halogen HPX lamp for 30 percent more light output for true tissue color and consistent, long-lasting illumination. It has a rotating lens with ultra-seal that allows for pneumatic otoscopy. Its fiber optic illumination produces cool light. It has a 10 Diopter lens, 2.5x magnification and comes with a set of 5 reusable ear specula. The 71000C universal rechargeable handle accepts all Welch Allyn 3.5v instrument heads. Its chrome-plated brass handle rests comfortably in the hand. It comes with an adjustable rheostat control; smooth, knurled finish; and safety switch to prevent accidental battery drainage. It can be recharged by plugging directly into a wall outlet. The 71000C model also includes a battery converter accessory that allows the handle be powered by C-cell batteries, a handy feature if you're on call or have forgotten to charge the battery.