Contactless Electric Whistle: The hand button whistle avoids mouth contact and requires no blowing to produce sound, making it ideal for use by multiple people, It offers a loud, clear and easily recognizable sound, Perfect for referee, coache, PE teacher, outdoor camp, sports events, traffic guides, pet train, and emergency self-defense Portable Whistle: Designed with a streamlined body for easy grip and comfortable use, It comes with a lanyard, allowing you to easily attach it to backpacks, camping gear, or carry in pockets, belts, or shoulder straps for quick access Long Life Whistle: Made from durable, impact resistant ABS material, it is nontoxic, odorless, and safe to use; Additionally, the whistle for teachers comes with four replaceable CR2032 batteries, allowing for quick replacement and eliminating the hassle of long charging times; If the sound weakens, simply replace the batteries Color: Black & Blue<br><br>Material: ABS<br><br>Package Contents: 1*Electronic Whistle<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.