Defender SN502-4CH-002 Feature-Rich 4-Channel H.264 DVR Security System with Smartphone Access and 4 Indoor/Outdoor Hi-Res CCD Night Vision Cameras The Defender SN502-4CH was first seen in early 2010.  It is a complete DVR security system equipped with the most modern features such as smart phone access, H.264 compression, as well as email alerts which allows you to maximize your security system in order to attain that high level of protection all the while keeping its user-friendliness.  This security system has been particularly designed for DIY purposes. Inside the Defender SN502-4CH-002 box you will find a four-channel H.264 DVR Continue Reading