New and high quality Mosquito repellent principle: The wristband achieves the effect of repelling mosquitoes by imitating the annoying sounds of female mosquitoes, such as male mosquitoes and dragonflies. In nature, the blood-sucking mosquitoes are all female mosquitoes, and they are all in the period of pregnancy and oviposition. In this price range, Female mosquitoes will avoid male mosquitoes and avoid second pregnancy. Therefore, the sound of simulating male mosquitoes can achieve mosquito repellent effect. Product features: purely physical mosquito repellent, not chemical drug repellent, safer, more assured, more environmentally friendly, and healthier. The elderly, children, pregnant women and pets can wear it. The product is portable and can be worn indoors and outdoors (seaside, park , camping, climbing, fishing). Material: PC, ABS Color: As shown Product model: M30 Function: Sonic mosquito repellent Input: 5V/0.5A Output: 34Hz-70KHz Battery capacity: 80mAh Charging time: About 30 minutes Endurance working time: 150 hours Package includes: 1pc Note: As different computers display different colors, thank you for your understanding, the actual product color may be slightly different from the image.