A single pack of refills for your MR300 Repeller or Bristol Lantern.Turn it on, Mosquitoes GONE! This 12 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: 3 repellent mats and 1 butane cartridge for a total of 12 hours of repellency