Exterminates flying insects Indoors and Outdoors. This electronic fly trap will eradicate flying insects, moths, flies, gnats, no-see-ums and other annoying flying insects from your home or area. It attracts, sucks and tucks them away with our specially designed no return cone screen. We tested the unit and found it works best for indoor use. We also recommend using it in an unlit room/area or overnight. FOR EXAMPLE: while working in the garage with the door open and lights on, flying insects were attracted to come inside because of the lights in the garage. Once finished, door shut, and lights off.. the next morning the bugs that had made there way in were all eliminated and the SLT trap was FULL of dead bugs! It generally takes between 4-6 hours to capture a good about of bugs. You can use the Dominator SLT outdoors, but it will not eliminate every bug out there. How about the ever annoying mosquitoes? We have mixed feelings as some folks say it has worked for mosquitoes and others have said it has not. Our option is that the SLT is not a great form of mosquitoes control for outdoors but will catch a fair share of them for indoors or outdoors. REGARDING PLACEMENT: The Dominator SLT Flying Insect Fan Trap really is made for a per room bases, Example: If I had a no-see-ums problem in my kitchen, I can not expect the SLT to clean up a fly problem in my garage. Meaning where ever the flying insect problem occurs that is where you want your Dominator SLT to be.