Turn it on, Mosquitoes GONE! This 120 hour refill pack is specifically designed to use with Thermacell Mosquito Repeller systems, including the MR300 Repeller and Bristol Lantern. __ Creating a 15 ft x 15 ft zone of protection against mosquitoes without messy lotions or sprays, each refill will provide 4 hours of protection.__Includes: 30 repellent mats and 10 butane cartridge for a total of 120 hours of repellency _