The ACR HotShot Signal Mirror is easy to use, floats, and comes with a whistle for low-visibility signaling. ACR makes aiming foolproof with a red holographic dot in the center window—just lay the dot over your target, and signal away. A foam floatation disc keeps the HotShot afloat in overboard emergencies, and an attached USCG-approved whistle pierces through fog and the dark of night.