The Rainbow Color Reader, model Mk2, is a color identifier designed for use by individuals who are blind or have low vision. This device identifies red, orange, yellow, gold, green, blue-green, blue, purple, pink, white, black, gray, brown, beige as well as light and dark. In combination, the device can identify 38 colors. To use, an individual firmly places an article flat against the plastic window at the end of the Rainbow Color Reader and then presses the button on the top. When held up to a light, the unit reads "light." The unit offers two volume levels for voice output. POWER: Uses 1 AA battery (included). DIMENSIONS (WxLxD): 2.8 x 2.2 x 0.95 inch.