Sun Company Therm-o-Compass - Zipperpull Compass and Thermometer | Easy-to-Read Outdoor Thermometer and Compass LUMINOUS COMPASS - Easy-to-read luminous compass keeps you on course, even in low-light conditions. THERMOMETER - Thermometer reads down to a chilly -20 F or -30 C. WINDCHILL CHART - View the simple windchill chart on the back of Therm-o-Compass to determine the "feels like" temperature. SPLIT RING - Solid brass split ring lets you easily attach Therm-o-compass to your zipper. the perfect zipper pull for you jacket, parka, or pack.