The ThermaCELL RB-1 Mosquito Repellent Refill Pack for Lanterns and Flameless Torch ensures that you are never left unprotected against biting insects. Keep insect pests away when using these replacement backs with any ThermaCELL appliance or lantern. The ThermaCELL repellent mat contains the active ingredient, allethrin, which is a synthetic copy of the natural mosquito repellent found in chrysanthemum flowers. ThermaCELL’s Mosquito Repellent mats are virtually odor-free and repel bugs without greasy, sticky, or oily sprays or lotions. Repellent mats are easy to use and require no open flame or messy wax to ignite. In order to continue to repel mosquitoes, black flies and other flying insects, repellent mats should be replaced every (4) hours. Mats can be used for short or long periods of time and ThermaCELL suggests to store in a dry, dark place between uses. Each ThermaCELL butane cartridge will last up to (12) hours and can be used for short or long periods of time. To ensure the life of each butane cartridge, make sure to turn off appliance or lantern after each use. The RB-1 Refill Pack comes with (3) repellent mats and (1) butane cartridge for a total of 12 hours of repellency. The ThermaCELL RB-1 Mosquito Repellent Refill Pack for Lanterns and Flameless Torches are only for use outdoors, do not use indoors or in enclosed spaces. Each ThermaCELL product features a warranty against manufacturer’s defects at time of purchase. ThermaCELL takes pride in creating products that are highly effective and make being outdoors more enjoyable. ThermaCELL and their parent company, Schawbel Corporation, are an industry leader in research, development, and engineering proven consumer products. ThermaCELL products that have been field tested by the Department of Defense and are endorsed by the North American Hunting Club, Good Housekeeping Institute and Parade Magazine.