I ordered the 1 1/2 acre unit. I have a 10 acre place. Put it in the middle where the house is-about 80 feet from porch. I have a really bad problem with mosquitoes and small biting black flies. I leave it on only at night and it is helping. I don't know if it is any better than any other bug zapper. But, it does what it says it will.  10/12/2016---Bought my second one. Item is a trure bug killer