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 (23810) 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 71000A 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.