Unlike outdoor clocks that require AC outlets and shroud the time in darkness when the sun sets, this one has LEDs that automatically illuminate when night falls. LEDs are placed at the noon, three, six, and nine-o'clock positions on the elegant Roman clock face, and they illuminate when the clock's built-in photocell sensor detects darkness, providing a soft amber glow. Two subfaces--a hygrometer and thermometer--indicate relative humidity and temperature; both instruments include re-calibration dials. Four D batteries (required) power the LEDs for three months; one AA battery (required) powers the clock's quartz movement for six months. The clock is made of steel painted in an antique bronze finish with an acrylic face. 18" Diam x 2" D. (1 lb.)