ISOTRONIC, Set of 3, Ultrasonic Mosquito Repeller with LED Flashlight and Keychain, 3 Pack , Repel Pest by Ultrasound Mosquito repeller with LED light, belt clip and keychain; Emit ultra high frequencies which can hardly be heard by humans to repel mosquitoes German engineered; Odorless mosquitoes repellent; No chemicals; No harm to humans or other animals Easy to use; Compact; Being protected from mosquitoes at home and outdoors Ideal for anglers, huntsmen, riders, campers, at open air swimming pools, when playing sports and games, when working outdoors, at home, in marshland and near water Operating area: Indoor/Outdoor; Effective range: 20ft (6m) radius; Power supply: 3 x 1.5 V AG 13 button batteries (included); Dimensions: 3.54" x 0.75" x 0.91" (90 x 19 x 23 mm)