VARIOUS USESSuitable for referee, trainer, teacher, sports, lifeguard, teacher, self-defense, survival, emergency, bird training, etc. HIGH FREQUENCY DESIGNThe whistle has large volume, long propagation distance, loud sound, strong penetration and high recognition. At the same time, the clear tone will not hurt the ears. The volume of the sound effect can vary from low to high. Depending on your whistle style, the volume will change, and the sound will be loud and clear. If necessary, you can quickly attract the attention of the crowd anytime, anywhere. HIGH QUALITY The corrosion resistant pipe is made of high quality stainless steel, which is safe, smooth and durable, far superior to plastic. Cleaning treatment - our stainless steel pipes are neither rusty nor waterproof. This can guarantee the service life of the pipeline. At the same time, care should be taken to ensure that there are no sharp edges in the production process. For internal or external professionals, this is a powerful tool. PORTABLE DESIGN The pipes are made of stainless steel to prevent rust. There are two ways to use the hose: you can hang it on your neck to free your hands, or you can hang it on the key ring to prevent loss. EXCELLENT PERFORMANCE The fitted hose can be held comfortably in the hand and can be grasped quickly. Therefore, even if you use it for a long time, your fingers or hands will not be tight and you will not feel tired. Suitable for left-handed users.