In addition to being a functional weather instrument our 17" outdoor hanging galileo thermometer is sure to be a conversation piece on any patio or covered outdoor setting. This thermometer reads temperatures between 60 and 100 degrees fahrenheit. There are 11 temperature spheres in red, cognac and blue colors. The temperature spheres are made of glass. The thermometer is made by a German company that has production facilities worldwide. The tags on the temperature spheres are 24-karat gold plated stainless steel. Just look at the lowest floating temperature sphere to tell the temperature. For optimal temperature reading and color life in the temperature spheres, hang your galileo thermometer under a covered patio, or somewhere out of direct sunlight. Your thermometer should be brought inside during inclement weather.