Easy to carry, strong and durable. Made by aluminum alloy material. Designed to alert anyone in the area and raise the alarm that you are in distress and need help. Sound power provides up to 120 decibels, enough to be heard at long distance. It's very sturdy but light. Emergency survival whistle is suitable for outdoor activities such as hiking, fishing, camping, boating, hunting and also for lifeguards, pet dog training. 2 3/16"L x 9/16"W x 5/16"H