The Thermacell Backpacker Mosquito Repeller keeps mosquitoes away with an invisible shield of protection and is designed specifically for your favorite outside area. It uses the same gas canisters (not included) that most campers and backpackers already have with them. It is compact, lightweight, and is a must for the outdoorsman while hunting, camping, and backpacking. It is virtually scent free and provides 15' by 15' Zone of Protection. On a 4 oz. fuel canister you will enjoy 90 hours of protection. The backpacker repels mosquitoes, black flies, and other flying insects. No spray, no mess, no smells, no DEET! The package contains: 1 Backpacker Repeller, 16 hours of repellent - 4 repellent mats lasting 4 hours each, and 1 water-resistant travel bag.