The EL Series ultraviolet lamps are manufactured with a durable, extruded-design metal housing and scratch resistant powder paint. Basic configuration offers one UV and one white light tube -- the advantage of white light or UV illumination from one unit. Use white light when working with materials in a dimly-lit area. Selected models use two tubes of the same wavelength or the 2UV™ Models use two different wavelengths. The 3UV Model™ available only in the eight watt lamp gives three wavelengths in one lamp. No other lamp offers this versatility.