Product DescriptionMaterial: ABSSize: 6.3*3 cmFunction: high decibel survival whistle, north (south) needle, thermometer, nylon ropeNylon rope factory: 40 cmColor: Army GreenQuantity: 3 piecesPackage content: 3 pieces * Three in one whistle1.3 in 1 multi-functions In addition to an emergency whistle, it is also a compass and a thermometer, providing you with necessary information during outdoor sports.2.The neck takes no burden for your outdoor sports, with neck strap easy to get in any situation, it can also be tied to your backpack, belt and so on. And it works quite well.3.Widely used High safety whistle for camping, hiking, cycling, skiing, all kinds of outdoor activities, and can also be for coaches, instructors, sports, teachers, lifeguards, protection, self-defense.4.The loud sound does not hurt your ears A whistle can save your life if there is an emergency on the water. The reason is that it is very difficult to scream if you fall into the water. In addition, vocal screams are really not very loud. A whistle will be much louder than a scream, so a whistle is a must for you out on the water. This is the tone you are looking for. Good sound, carries a good distance, does not hurt your ears when you blow it. 5.Durable and loud Just the right pitch and trill to command authority. The ball inside can freeze in very cold weather. If this happens to you, try spraying some dry silicone inside to cover the ball. I expect this is common for most whistles of this type. EASY TO HEAR - 3 super loud survival whistles can produce up to 120 decibels of guaranteed sound, can be heard from a long distance and play their role in emergencies.