Great for any outdoors person. Use as a zipper pull, key ring or hang on a backpack. The thermometer tube is sealed inside a clear acrylic case with a handy wind chill chart on the back. Fahrenheit/Celsius temperature scale. Range -20 to +120 degrees F and -30 to +50 degrees C. Dimensions: 1 1/8"x 2". Wt: 0.3 oz.