Our most advanced repellent system ever, the rechargeable E-55 Mosquito Repellent keeps mosquitoes away, without spray. Within minutes, the system heats and activates our scent free, invisible repellent, protecting outdoor spaces from mosquitoes. The E-Series is ideal for patios, poolside, decks, or just about any outdoor space. Its effectiveness is unmatched by candles or torches. [Wirecutter magazine called it .]. Like all Thermacell repellents, the E-Series been evaluated by the PMRA for safety and effectiveness. Rechargeable and long-lasting, the E55 comes with a 12-hour repellent refill cartridge and includes a USB cable for charging. The E-Series is incredibly effective many times more effective than candles or torches. And its environmentally friendly.