Defender Sentinel Pro Wireless Security System 4 CH 1TB DVR with 4 Wireless 520TVL Cameras with 100ft Night Vision, 21305 ClearVu Digtal Wireless Technology 750ft Range of Private and Secure Digital Signal 4 Weather Resistant 520 TVL Cameras with 100ft Wide-Angle Night Vision 1TB HDD Delivering Four Years worth of Storage 1 Step Remote Viewing Software for Viewing Footage on your Smartphone