Feature: 1. Bracelet achieves the effect of repelling mosquitoes by imitating the sounds of female mosquitoes, such as the sounds of male mosquitoes and dragonflies. 2. Pure physical and non?chemical mosquito repeller is safer, more environmentally friendly and healthier. 3. The elderly, children, pregnant women and pets can wear it to protect you from mosquitoes. 4. You can wear it indoors and outdoors (sea, parks, camping, rock climbing, fishing). 5. Ultrasonic mosquito repellent bracelet is easy to use and can be used when you turn it on. Specification: Item Type: Mosquito Repellent Bracelet Material: Silicone + Plastic Product Model: M30 Input: 5V / 1A Output: 20Hz-100KHz Battery Capacity: 100mAh, polymer battery, built-in Charging Time: about 30 minutes Working Time: 150 hours Weight: Approx. 41g / 1.4oz . Package List: 1 x Mosquito Repellent Bracelet1 x Charging Cable1 x User Manual