S4Optik H5 Slit Lamp Video Ready The SL-H5’s parallel optical system allows the addition of digital imaging systems so digital documentation can be simply achieved. Mechanical Excellence Precision machining and European craftsmanship delivers silk smooth base movements for effortless positioning and fine detail work. Quality materials ensure longevity of performance and superior return on your investment. A base mounted rheostat to control slit illumination is standard for optimal ease of use. This convenient positioning allows effortless, yet precise control of slit illumination.