Thermacell Halo Mini Mosquito & Midge Protector; Includes 3x4hr Mats & 1x12hr Cartridge; DEET-Free; Scent-Free; No Smoke; 20 sqm Protection ZoneThe Thermacell Halo Patio Shield Mosquito protector effectively preotects from mosquitoes and midges by creating a 20sq metre zone of protection. This compact, easy-to-use and stylish device will look great on any patio or deck while it works to keep annoying mosquitoes & Midges from biting and bothering you and your guests.Thermacell Large Refill Pack (Mats and Gas)The Thermacell mosquito protector refill large pack contains 4 butane cartridges and 12 insect protector mats. Each cartridge lasts up to 12 hours and each mat lasts up to 4 hours. The repellent mats utilize the synthetic chemical allethrin that repels up to 98% of mosquitoes, black flies, and other pests. The mats feature an earthy, natural dirt scent that helps mask human scents. Once warmed up, the unit provides protection to a 20sq metre zone.