Windsor Electronic Whistle - 3 TonePersonal safety and signaling device. Loud consistent sound every time. Referees and coaches find it easier to give verbal commands without a whistle in their mouth. Each set of "AAA" batteries produces more than 1000 blasts. Loud 105 dB whistle sound can be aimed in the exact direction intended and away from user. Hand operated instead of mouth blown for better hygiene. 4" long. Unit of Sale : Each