I purchased the Good Knight Advanced Activ+ System for mosquito security, and I thought twice about it. The item didnt satisfy my hopes. Notwithstanding turning it on for a few hours, I may as yet hear mosquitoes humming around. The top off cost was high and required to have been supplanted every now and again. I even took a stab at changing the top off, however it didnt work. Im disheartened and feel cheated as I suspected this item was progressed and successful. It is a finished misuse of cash, and I dont suggest it.