This Large Zapper kills House Flies, May Flies, Deer Flies, Horse Flies, Mosquitoes, Yellow Jackets, Hornets. Wasps, Spiders, Cockroaches, Centipedes, and Moths. This unit has 1500 volts of power with protective screens. It is 21 1/2 inches long. 8.5"x10" head and weighs a 14 ounces with two D batteries.