ULTRASONIC TECHNOLOGY: By 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), thereby achieving mosquito repellency. SECURITY: Our electronic mosquito repellent bracelet, ultrasonic to create a sound barrier, pure physical mosquito repellent, chemical-free, safer, more environmentally friendly, safer, healthier, than the old, children, pregnant women and pets can wear. USB CHARGING: Smart charging mosquito repellent 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 indoor mode; press again to change outdoor sports mode; press again a third time to activate silent standby mode; press a fourth time to turn off the device. WIDELY USED: Whether you're camping, fishing, hiking or in the parks in the jungle, deet free smart mosquito repellent is the best mosquito repellent formula for the jungle as a baby float or adult waterproof poncho camping beds camping chair for kids or swimming aids for toddlers accessories good body boards. Number of shipments: 1 pcs