The Forecaster 610 by Silva is a compass and thermometer combination. The Forecaster is Silva's accurate, and easy-to-read compass duo that enables clear temperature readings. The Forecaster thermometer shows both Celsius and Fahrenheit measurements. Using the Forecaster Compass is easy--the 5-degree graduation is simple and clear. On the back of the Forecaster is a convenient wind-chill table. The metal loop on the Forecaster 610 is great for adding to a set on a key chain, or attaching to a zipper pull.