Lifesystems Dual Mosquito Killer: Helps reduce the danger and annoyance of mosquito bites during the night. The simple device plugs into the mains and slowly heats either a liquid or a tablet to emit an odourless scent that is harmless to humans, but extremely effective against biting insects. Entomological research has shown that electric mosquito killers of this type start knocking mosquitoes down less than a minute after being plugged in. The unit is supplied with a bottle of the liquid that provides up to 40 nights* protection before it needs to be replaced. Alternatively, tablets can be used.