PIC Mosquito Repelling Coils have been repelling mosquitoes since 1953. Perfect for patios and porches. For Outdoor use only. Keep your backyard and patio free from pesky mosquitoes with these Mosquito Repellent Coils from PIC! Just light the coil like a candle and let it burn, repelling mosquitoes and saving your skin from bites. Each coil lasts 5-7 hours and repels mosquitoes in a 10-foot radius.