In a pinch, you can use almost any reflective surface — even the shiny material from the inside of a broken cell phone — as a signal mirror [source: Galloway]. But survival experts say that you'll have the best chance of contacting rescuers if you use a mirror specially designed for signaling. You want one that's big enough to comfortably fit in your hands — a 2-by-3-inch (5.1-by-7.6-centimeter) size is good — with a small hole in the middle that enables you to see where you're focusing your signal [sources: McDougall, Nester]. That way, you'll capture the eye of a search team, rather than, say, a deer or squirrel.
Some experts advise buying a plastic mirror that's light enough to be manipulated with one hand and resistant to breaking [source: Murray]. But others recommend glass mirrors, which can reflect sunlight much farther. So use your own judgment on that. If you opt for glass, carry your mirror in a Bubble-Wrap sleeve to prevent it from being damaged [source: Nester].
You can purchase a good signal mirror for less than the cost of a pair of pants. One outdoor outfitter's Web site, for example, offers a spiffy model that's equipped with a special viewing window that superimposes a red dot on your target, so that you can pinpoint exactly where you are focusing your signal. It even comes with an attached whistle to help rescuers zero in upon you, and it costs just $15.
Practice using your mirror before setting out on your next outdoor adventure. We have instructions on the next page.