Pifpaf liquid machine uses a brand new stable temperature PTC heating element.This absorbs the liquid through the wick and evenly distributes the active in the air via heating action.Since the active is released into the air PIFPAF liquid Mosquito killer effectively knocks down mosquitoes even those hiding in corners.I has cordless design and is convenient and safe to use Long Lasting Mosquito Killer ,no need to change every day. Used 8 Hours per night