3 function: whistle, Waterproof thermometer, Waterproof compass Temperature range: -20 50 degrees Celsius, Size: 2.4*1.2*1.2 inch. Comes with Lanyard. On one side there is a compass, and the other is Celsius thermometer. Durable plastic whistle and nylon neck lanyard. Great for camping, hiking, hunting, fishing, boating, outdoor activities, travel, emergency/survival kits, etc. Three colors are available: army green, black, and white."