Features 1. Mosquito repellent principle: The wristband achieves mosquito repellent effect by imitating the sounds that female mosquitoes dislike, such as the sounds of male mosquitoes and dragonflies. In nature, female mosquitoes are the ones who feed on blood and are in the period of conception and egg laying. At this price range, female mosquitoes will avoid male mosquitoes to avoid secondary conception. Therefore, simulating the sound of male mosquitoes can achieve mosquito repellent effect 2. Pure physical mosquito repellent, not chemical mosquito repellent, safer, more reassuring, more environmentally friendly, and healthier. It can be worn by the elderly, children, pregnant women, and pets. The product is portable and can be worn both indoors and outdoors (by the sea, in parks, camping, hiking, and fishing). 3. Ultra long battery life: Fast charging, 30 minutes per charge, can work for 130 hours, standby for 1 month, long battery life. 4. Three level driving setting: When the power is turned on to first level, for daily indoor use, press the button again to switch to second level outdoor sports mode, press the button again to switch to third level, silent mode. Specification Product model: M1 Function: Ultrasonic mosquito repellent Input: 5V/1A Output: 34Hz-70KHz Charging time: about 30 minutes Battery life: 130 hours Material: Silica gel Color: Black, White Size: 25.5 x 2.7 x 2.4 cm Weight: 55 g Package Include: 1x Anti-mosquito silicone wristbands