3-in-1 multi-function, in addition to emergency whistle, it is also a compass and thermometer, bringing you the information you need for outdoor sports. You can use your favorite lanyard instead of nylon lanyard. Will not bring any burden to your outdoor sports, the neck lanyard can be easily accessed in any situation, it can also be tied on your backpack, belt, etc. You can tie it to your PFD and it works great. Loud safety whistle for camping, hiking, biking, skiing, any type of outdoor activities, also can be used for coaching, coaching, sports, teachers, lifeguards, protection, self-defense. In the event of an emergency on the water, a whistle can save your life. The reason is that it's really hard to scream if you fall into the water. Plus, the vocal screams are really not very loud. A whistle is much louder than a scream, so a whistle is a must-have for going out to sea. This is the tone you're looking for. The sound quality is good, the transmission distance is long, and it does not hurt the ears when blowing. Durable and loud. Just the right pitch and vibrato to command with authority. In very cold weather, the ball inside may freeze. If this happens to you, try spraying some dry silicone inside to cover the ball. I expect most whistles of this type are common.EASY TO HEAR - 3pcs Super Loud Survival Whistle is guaranteed to deliver up to 120 decibels, which can be heard from a distance and function in an emergency.