Two-sided design provides emergency signaling capability day or night. Silver daytime mirror reflects the suns rays to attract attention to your location. Red side can be used as a nighttime signaling device by shining a focused flashlight or headlamp beam into the mirror. The reflection created by a flashlight beam on the red mirror is visible up to three miles depending on conditions. Comes with polyester lanyard measuring three feet, for easy attachment to a lifevest or pack. Made from shatterproof polycarbonate; because its waterproof and saltproof, it will not lose its reflective qualities.