The JetScream Micro whistle is a powerful signaling device for use during emergencies or in survival situations. At 112dB, its ear-piercing shriek can be heard above most natural and man-made noises. The whistle's pea-less design won't freeze or clog, and is just as effective when wet.The JetScream Micro Whistle is the "micro" version of our best-selling JetScream whistle!.