Best purchase I ever made.  Used to get attacked by mosquitos out by my pool and pergola area as soon as it got dark.  Bought one of these and put it up at the back edge of the property and it knocked down the mosquitos substantially to the point they were barely a bother.  Since then we bought a second one and always put them out in early spring to stay ahead of the mosquitos and it works great.  They are on a dusk to dawn timer so they work all night for us.  We clean them up every fall when we put them away.  Otherwise they are pretty much maintenance free.  The bulbs are a little expensive but there's some generic units out there that work just as well as the ones flowtron sells.