ULTRASONIC TECHNOLOGY: Using biological sound waves (ultrasound + bionic waves), double-wave ring overlapping sound playback, you can imitate the sound of female mosquitoes (male mosquitoes and cockroaches), thus achieving mosquito repellence. SAFETY: Our electronic mosquito repellent wristband, ultrasonic to create a sound barrier, pure physical mosquito repellent, no chemicals, safer, more eco-friendly, more assured, healthier, the old, kids, pregnant women and pets can wear. USB CHARGING: Smart charging anti-mosquito bracelet, built-in smart chip, USB fast charging, charging 30 minutes, standby time 30 days, use 150 hours, save time and trouble, effectively avoid more than 90% of mosquitoes. THREE MODES: Press once to turn on the switch to start the indoor mode; press again to switch the outdoor sports mode; press again for the third time to turn on the silent sleep mode; press the fourth time to turn off the device WIDELY USED: Whether you are camping fishing hiking or parks jungle shopping smart deet mosquito repellent free is the best jungle formula mosquito repellent as baby swimming float or poncho waterproof adult Wear it in camping beds kids camping chair or toddler swimming aids It is base kids bike accessories good body boards.