If multi-usability is key then the Coghlans Six Function Whistle is an excellent piece of kit. Use the whistle and signal mirror in an emergency to attract aid. The compass will help you find your way and the LED light will show you where you're going at night. Take a closer look at those tiny flowers and curious insects with the magnifying glass. The thermometer will tell you just how hot or cold it's really gotten and the clip lets you keep this fun gadget handy attached o your knap sack.