Stylish useful Ultrasonic Pest Mosquito Repeller Bracelet Belt Clip The Mosquito Repeller uses an advanced technolgy insect repellent that makes outdoor living and acttvttte s more enjoyable from the annoyance of mosquitoes. It works to help protect you while you're fishing, camping, hiking, jogging, on the golf course, or just at ease on your patio or porch Use a coin to twist the cap open insert one CR2032 button cell battery (Included). Locate the frequency switch on the stde of the device: Male mosquito setting / Dragonfly setting / Power off. Not all mosquitoes are deterred by same things.Try each setting for 15 minutes or so until satisfactory results have been achleved.