1. [Multifunctional Electronic Whistle] The electronic whistle is suitable for physical education teachers, coaches and referees, sports training, outdoor camping, training, hiking, and survival emergency electronic dog whistles. It not only has the function of whistling collection, but also has the function of saving lives!2. [Electronic whistles are widely used] Electronic whistles have all the functions of common whistles such as sports training, ball coaching, pet training, emergency response, outdoor activities, archery guidance, firearms coaching, etc. The decibels are high and the sound penetration is strong, even if you use it outdoors.3.High Volume HandheldPersonalized whistles for you to choose from. The lightweight and portable whistle is easy to carry. Please do not point the speaker at people's ears to avoid damaging the eardrums.4. [High Quality] Our sports electronic whistle is made of high quality ABS environmentally friendly material, which is odorless and healthy. The crack-resistant and sturdy design makes this electronic whistle durable for long-term use.5. [Loud enough and adjustable tone] The sound of the electronic whistle is loud enough to cancel all noise and be heard. The tone is adjustable, which is a nice change from a regular whistle. You can adjust the tone as needed, not just in small spaces but in open spaces as well.product detailed information:Battery life: 200 minutesCharging time: 3-4 hoursPower capacity: 500mAhCharging power supply: 5V1APower supply: polymer lithium batteryProtection level: IP54Static operating current: