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 Long-lasting mosquito repellent: Smart charging anti-mosquito bracelet, built-in smart chip, USB fast charging, charging 30 minutes, standby time 30 days, use 130 hours, keep the mosquitoes bugs insects away from you and your kids effectively. Stylish & lightweight Available in black stylish and portable with adjustable skin-friendly silicone strap Say goodbye to the skin of the herbal bracelet to prevent harmful chemicals no smell suitable for babies kids children and adult No need insect bite relief bug spray or mini first aid kit mosquito repellent spray 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. Enjoy the Great Outdoors & indoor in Comfort: Our mosquito repellent bracelets are small & comfortable to wear. If you often go on vacations or do outdoor activities it can be concern. It is perfect for holidays, outdoor meals, hiking, camping, jogging or fishing. Function: Mosquito Repellent Input: 5V/0.5A Output: 34Hz-70KHz Battery capacity: 80mAh Charging time: about 30 minutes Endurance working time: 150 hours Color: black, white, blue, pink Package Included: Mosquito Repellent Bracelet*1 USB Cable*1