Exclusive dustproof design protects the precision optical components and ensures maintenance-free operation. The BETA200 / 200 S Ophthalmoscopes are the only instruments with an aluminium frame system. Optical components are flush-mounted on a cast aluminum frame, eliminating misalignment and making the instrument shock-resistant.XHL Xenon Halogen bulb with bright illumination and authentic colour rendering. Range of lenses: 27 lenses from -35D to +40D. Without macula aperture (pinhole). Exclusive continuous brightness control between 100 % and 3 (patent pending) with one-finger operation. No stray light due to the recessed, multi-coated viewing window – eliminates distractions. Precise one-hand control of the instrument. Ergonomic design offers flexibility while examining. Suitable for large as well as small or undilated pupils. Ergonomic design fits the orbita comfortably, and blocks out ambient light.