The Storm Whistles are twice as loud as most popular whistles and capable of being heard above howling wind or any competing sound. It even works under water. Two sizes available: Storm 3" x 2", Wind Storm 2.5" x 1.6". Orange casing. 2 5/8" overall. Easy to grip high-impact thermoplastic construction with keyring. Extremely loud for personal protection. Can be heard above crowds, howling wind or virtually any competing sound. Will perform in any wet or dry environment. Sound will discharge above, on or below the water. Ideal for sporting events, campers, hikers, boaters, hunters, scuba divers, and game officials. Adopted by the U.S. military. Hang packaged.