The Thermacell Patio Shield Mosquito Repeller Lantern XL (formerly Cambridge Lantern) effectively repels mosquitoes by creating a 15-foot zone of protection. The decorative black lantern provides ambient lighting with warm LEDs to adorn your deck, patio, or campsite. The lantern and repellent can operate independently or together. It is ideal for use while gardening, observing outdoor sporting events, and is perfect for your patio while hanging around the backyard. To use, simply insert a repellent mat and a fuel cartridge, then turn it on. The fuel creates heat. A view window lets you check for an orange glow to ensure the heat is on. Heat activates the repellent in the mat. After 15 minutes, a mosquito protection zone is formed. The repellent mat turns white after about 4 hours indicating it’s time for the mat to be replaced.