content: I've used the Voice Alert System for about a month now. It works good but does false trigger some. I've tried moving the sensor and adjusting the sensivitity and it has helped. I may just need to tweak it a little more. It has never failed to trigger when someone has entered the area, which is the important part. I don't know that I would hook it to a siren but I'm very happy with the system. Instructions that come with the unit are very good but where a little unclear about how to hook up the external devices to be trigged. I plan to add a light to be activialed in the warehouse for night. I did buy an extra sensor for the driveway and some of the false alerts there are casued by birds flying in front of the sensor. It's a good 120' away and the base unit is inside a brick building in an interior room (2 walls). It picks up all traffic in the drive. Good system for the money.