Supernew Electronic Whistle with USB Charging Emergency Whistle for Referee Coaches Teacher for Outdoor Sport Game Camping Compared with traditional whistle,Electronic whistle can avoid mouth contact. Just press the sound button then it will bring a loud and clear sound. which saves effort and prevents spatter of saliva between users. Whistle with lanyard perfect for referee coaches, P.E. teacher, marine, outdoor camping, sports competitions, traffic guides, pet training, self Defense Emergency._x000D_ electronic whistle have 3 different tones to meet different needs, All the tone are high volume, can provide up to 120-150 dB sound power. Our mouth-free whistle is made of high quality ABS material, very sturdy and durable. It also has no any release of harmful substances. Easy to get attention and USB direct charging and thus much convenient environmental and save the cost._x000D_ The electronic whistle with USB charging,It is 10 times more durable than ordinary button batteries., can keep sounding for 4 hours and save the cost of buying batteries. It also has led lighting function,which can assist in lighting in dark environments. Easy to use. It has a comfortable ergonomic design with one-handed operation, and a detachable lanyard for convenience._x000D_ [Easy to Carry]Hand whistle equipped with a long lanyard, it can easily loop through backpack, sailboats, camping hiking gear, life jacket, kayak . You can also tie the whistle to your neck, shoulder straps, belt and backpack or put it on the pocket for quick and easy use in case of emergency._x000D_ _x000D_ Colour:Black_x000D_ Material:plastic_x000D_ _x000D_ Package Contents:_x000D_ 1 x Electronic Whistle_x000D_ 1 x usb cable(Color and style are random, don't accept the specified)_x000D_ 1 x Lanyard(Color and style are random, don't accept the specified)_x000D_ _x000D_ Only the above package content, other products are not included._x000D_ 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. _x000D_ _x000D_ _x000D_ _x000D_ _x000D_ _x000D_ _x000D_