Now here’s a handy little 3-in-1 tool that combines a whistle, compass, and thermometer in one small package. Well designed too, the compass and thermometer are liquid-filled for easy reading and the compass dial is luminous. The whistle is loud and comes with a nylon lanyard, 43cm long. The whistle has a pea and will not work underwater, but will work when wet.

• Temperature range: -30°C to +60°C

• Dimensions: 3.0cm x 5.9cm x 2.9cm