Features1. Energy-saving: Ultrasonic mosquito repellent built-in smart chip, USB fast charging, It takes 30 minutes to charge, the full power can be use last for one week. The internal USB-charged battery holds a long life and reusable. 2. Adequate Security: Pure physical ultrasonic mosquito repellent, no chemical additives, no radiation, no odor, completely safe for the elderly, pregnant women, children, and pets, environmentally friendly. No harm to health. 3. Three Modes: The power is turned on as first gear, suitable for outdoor sports and activities. Press again for the second gear, suitable for indoor use, press for the third gear, switch to silent mode. 4. Wide Use: Ultrasonic mosquito repellent wristband suit use for all occasions such as indoors(sleeping, working, reading and so on)and outdoor(camping, sports, barbecue, fishing, hiking, doing and so on). This design makes the mosquito bracelet almost suitable for everyone. 5. Perfect Gift: This anti-mosquito bracelet is stylish, lightweight, high-end technology, suitable for birthday gifts, Mother's Day and Father's Day gifts, can protect you and your loved ones protect yourself from mosquitoes and enjoy the perfect summer.Specification Material: ABS, Silicone Color: Black, White Size: 26 x 2 cm Weight: 20 g Input: 5 V/1 A Output: 34 Hz-70 KHz Battery Capacity: 90 mAh Charging Time: About 30 minutes Version: Standard Edition, Flagship VersionPackage Include: 1 Wristband 1 Charging Cable 1 Manual