product descriptionMaterial: ABSSize: 6.3 * 3 cmFunction: high decibel survival whistle, north (south) needle, thermometer, nylon lanyardNylon rope factory: 40 cmColor: Army GreenQuantity: 3Package Contents: 3*3 in 1 whistle1.3-in-1 Multifunction Besides emergency whistle, it is also a compass and thermometer, bringing you essential information for outdoor sports.2. Neck strap You can use your favorite lanyard instead of nylon lanyard. Bring any burden to your outdoor activities, the neck lanyard is easily available in any situation, it can also be attached to your backpack, belt, etc. good results.3. Widely used for camping, hiking, biking, skiing, any outdoor activities, and also for coaching, coaching, sports, teachers, lifeguards, protection, self-defense.4. Loud sound does not hurt the ears If there is an emergency on the water, the whistle can save your life. The reason is that if you fall into the water, it's really hard to scream. Also, the scream of the voice is really not that great. Whistles are much louder than screams, so you have to whistle when you are on the water. This is the tone you are looking for. The sound is good, the distance is great, and it won't hurt your ears when blowing.5. Durable and Loud Just the right tone and vibrato to command authority. In very cold weather, the balls inside can freeze. If this happens to you, try spraying some dry silicone on the inside to coat the ball. I expect this to be common to most whistles of this type. EASY TO HEAR - 3 ultra-loud survival whistles provide up to 120 decibels of sound guaranteed to be heard from a distance and useful in emergency situations.