I had purchased the main CCTV system in March and needed some additional camera's. I did not find sales very helpful when trying to check the compatibility of the additional camera's with my previous purchase. In fact I had to ask if I needed any additional items, such as cables. It would have been good for sales to have advised I also need a PSU. Having used the system now I find it to be good however to view it over the web required your browser to be able to support Quick Time, which is an issue. The CCTV software seems somewhat dated with limited or no support for mobile devices.