Wind Storm Safety Whistle, this is the smaller version that can easily fit into your pocket, Waterproof. Suitable for Hikers, Campers, Scuba Divers, Police, Firefighters

A high-impact, non-corroding thermoplastic protective housing is easy to grasp, and the patented double chamber design allows it to be blown when held right side up or upside down, forcing all water to be purged when the whistle is blown.