Product Description Material: ABS Size: 6.3 * 3 cm Function: Gaofenbei Lifeguard, North (South) Needle, Temperature Gauge, Nylon Rope Factory: 40 cm Color: Military Green Quantity: 3 pieces Packaging Content: 3 pieces * Three in one whistle 1.3-1 multifunctional In addition to emergency whistle, it is also a compass and thermometer, bringing you necessary information during outdoor sports. 2. You can use your favorite hanging rope instead of nylon hanging rope for the neck strap. It won't burden your outdoor activities, and the neck rope is easy to reach in any situation. It can also be tied to your backpack, belt, etc. And the effect is very good. 3. A loud safety whistle widely used for camping, hiking, cycling, skiing, any outdoor activity, and can also be used for coaches, trainers, sports, teachers, lifeguards, protection, and self-defense. Loud sounds will not harm your ears. If there is an emergency on the water, a whistle can save your life. The reason is that if you fall into the water, it's difficult to scream. Moreover, the loud screams are not really very loud. The whistling sound is much louder than the screaming sound, so be sure to whistle when you go into the water. This is the tone you are looking for. The sound is very good, far away, and it won't hurt the ears when blowing.