Mosquito repellent refill. Thermacell's award-winning technology keeps mosquitoes away by creating a 20-foot protection zone around you. The proprietary formula precisely targets mosquito sensors, driving them away. With consistent protection that doesn't weaken over time, Thermacell helps you live your best outside life without the use of bug sprays or lotions on your skin. Always be prepared by keeping extra cartridges in your tent, backpack, garage, or tackle box ready when you need it. Portable and allowed to bring on airplanes. Compatible with Thermacell Rechargeable Repellers only.