This portable set features Welch Allyn's finest diagnostic instruments. The 11730 3.5V Coaxial Ophthalmoscope Head features precision optic with 68 lenses in single-diopter steps (+38 to -30). Halogen lamp illumination insures true tissue color and a Polarizing filter virtually eliminates corneal reflection. The MacroView Otoscope (23820) uses Halogen HPX lamp and fiber optics for cool light with no reflections, no obstruction. It comes with a built-in throat illuminator/penlight and a wide-angle viewing lens for instrumentation under magnification. The 3.5V Nasal Illuminator from Welch Allyn (26535) is three instruments in one. It facilitates easy nasal examinations with halogen HPX illumination for true tissue color and a reusable tip. As a bonus, the head can be detached to use the illuminator as a throat illuminator or penlight. 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.