Rechargeable Repellent Refills keep your devices running for the long haul. Featuring a 20-foot zone of protection against mosquitoes - our largest zone yet. Always be prepared by keeping extra cartridges and mats in your tent, backpack, garage, or tackle box ready when you need it. Portable and TSA compliant for air travel. (Compatible with Thermacell Rechargeable Repellers only.) Features: Rechargeable Refills create a 20-foot zone of protection against mosquitoes - our largest zone yet. This cartridge is compatible with all Thermacell rechargeable repellers. Each scent-free refills provide 36 hours of on-demand, continuous mosquito protection. Portable and TSA-compliant. Thermacell rechargeable devices are powered by a lithium-ion battery. Heat activates the repellent to provide maximum protection in 15 minutes. Portable and TSA compliant. Repel mosquitoes without DEET sprays or lotions on your skin. No smoke, flames, or strong scents like citronella. Independently tested and EPA reviewed for safety & effectiveness. People and pet friendly. Backed by the Thermacell Guarantee. See packaging for details. Includes: One 36-hour repellent refills.