For the backyard and beyond, Thermacell Rechargeable Repellent Refills keep your devices running for the long haul. Featuring a powerful zone of protection against mosquitoes. Always be prepared by keeping extra cartridges in your tent, backpack, garage, or tackle box. Portable and air travel friendly. (Compatible with Thermacell Rechargeable Repellers only.)EFFECTIVE REPELLENT FORMULA: Thermacell Mosquito Repellent Rechargeable Refills create a powerful zone of protection against mosquitoes. 40-hr refill compatible with all Thermacell rechargeable repellers.LONG-LASTING DEFENSE: Scent-free refills provide 40 hours of on-demand, continuous mosquito protection. Portable and air travel friendly.HEAT-ACTIVATED TECHNOLOGY: Thermacell rechargeable devices are powered by a lithium-ion battery. Heat activates the repellent to provide maximum protection in 15 minutes.REPEL WITHOUT SPRAYS OR SCENT: Repel mosquitoes without chemical sprays, lotions, or DEET on your skin. No smoke, flames, or scents. Independently evaluated for safety and effectiveness. People and pet friendly. Always use as directed.THERMACELL GUARANTEE: Backed by the Thermacell Guarantee. See packaging for details.INCLUDES: One 40-hour repellent refill.