The 18321 set includes an ophthalmoscope, retinoscope, rechargeable handle and hard case. The Welch Allyn 3.5v Standard Ophthalmoscope (11710) features halogen light for true tissue color and consistent, long-lasting illumination and 28 focusing lenses. The Streak Retinoscope (18200) enables easier and quicker refractions with a crossed linear polarizing filter that eliminates bothersome glare from trial lenses. Sealed optics keep the lenses cleaner. The rechargeable handle (71000A) has an adjustable rheostat control. Its free-floating reserve setting allows optimal intensity and battery life. The convenient built-in charger allows you to plug into any conventional wall outlet for overnight recharging. Its chrome-plated brass handles provide durable, long-life construction. It has a safety switch to prevent accidental draining of the battery. Metal head connectors for durability.