The 18320 set includes an ophthalmoscope, retinoscope, rechargeable handle and hard case. 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 Streak Retinoscope (18245) makes refractions easier than ever by producing one of the brightest, sharpest, and cleanest streaks available. It provides 2.8X the brightness of Welch Allyn's standard retinoscopes. Enables easier and quicker refractions-even in patients with small pupils. Crossed linear polarizing filter eliminates bothersome glare from trial lenses, helping you perform a more precise exam. The external focusing sleeve improves comfort and maneuverability. 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.