I bought this to protect our birdtables as recommended by the RSPB. Boy does it give the cats a scare, but they leave at least dry and unharmed. I have a small town garden so one of these covers the feeding stations no problem but you can daisy chain more than one unit with extension cables from one mains adaptor without too much trouble (purchased seperately) Alternatively you can run these with a 9v battery, battery life depends on how much action passes in front of the PIR. It\'s a breeze to set up and has great coverage and is easily tested via a flashing red light, that goes on when a cat comes in it\'s path.Get one and let the feasting continue without murderous intruders!!