• Lightweight 7 in 1 multifunctional survival whistle.Seven functions in high decible whistle, compass, thermometer with range from -20 °C to 50 °C, magnifying glass, reflector , led light and small sealed compartment.Material: ABS.Color: Black & SilverSize: 2.5x10.8cm / 0.98x4.25inch.A conversion chart for angle, gradient, and distance appear on the back of the compass, and a rotating bezel ring allows you to lock in your bearing so you know you are heading in the right direction.