Item Type: Electronic Whistle Material: ABS Color: As shown in the picture Length: Approx.15cm/5.9in Weight: Approx.81g/2.9oz Battery: 4 x 1.5V CR2032 button battery (not included)  How to Use 1.Put in the battery (not included). 2. There is a gear button on the side of the whistle, 4 gears (OFF/1/2/3), three different whistling can be adjusted. 3. Press and hold the sound button in the middle of the whistle, the whistle will sound. 1、Ideal for traffic commandos and lifesaving, military training, sports competitions and training, and pet training.  2、Suitable for referees, coaches, travelers, adventurers, guides, cheerleaders, lifeguards, teachers, transportation guides, seniors, etc.  3、The cylindrical shape of the pronunciation mouth, the sound transmission distance is long, and can be heard from a distance.  4、Portable size, light weight, come with a lanyard, easy hanging around the neck, easy to carry.  5、There is a gear button on the side of the whistle, 4 gear positions (OFF/1/2/3), three optional sound effects, and the sound is clear.