Come and Check Our Promo Solutions.The flat whistle is made of eco-friendly ABS plastic and comes with a chain ring ,which is bump-proof, weatherproof. Three sound chambers design, high pitched noisemaker, audible over 1 mile, easier to be heard, work great as a signal whistle. Whether you're going for camping, hiking, fishing, hunting, kayaking, snowboarding or skiing, our whistles are tailored for any outdoor adventure. It can be attached on your backpack, life-jacket, belt, shoulder strap and much more. Pls check inventory and detailed info with us before placing your orders.