According to the research of insect ecology, most of biting mosquitoes are female ones in spawning period. A spawning female mosquito is very disgusted at the approaching of male mosquito. Therefore, the frequency of personal electronic mosquito repeller is made to imitate the sound signal of male mosquitoes to repel female mosquitoes away. Keep one personal electronic mosquito repeller, keep away from mosquito. Features : 1. Emits high-frequency, audible sonic waves that drive mosquitoes away. Easy to use and will not irritate user. 2. Lightweight and portable. Can be clip it to the pocket or belt. 3. No fumes, no odors. Will not harm to humans and pets. 4. No chemicals, no sprays, no smell, no mess, no electrical plugs, and non-hazardous. 5. One AA size (UM-3) battery lasts for 3 months when continuously used. 6. Effective range : 3~5 meters (10~16 feet).