GWSecurity 4CH400WHD 4 Channel DVR + 4 x 1000TVL (720P) Vari-Focal Zoom 147 feet IR Outdoor / Indoor Security Camera System with Pre-Installed 1TB Hard Drive

What lens do I need covering an angle of?
Please view the table below:
Focal Length: Angle of View
2.8mm: 97.4 degrees
3.6mm: 85 degrees
4mm: 71.6 degrees
6mm: 44.4 degrees
8mm: 34.5 degrees
12mm: 22 degrees

Overview
960H High End 4 Channel HDMI & VGA DVR with 4 x 1/3" Color SONY CMOS Outdoor or Indoor Camera, 1000TV Line, 2.8~12mm Manual Varifocal Lens. 960×480 & 30FPS recording, iPhone, Android Viewing. Network live, playback

DVR Feature
*4 Channel H.264 video compression format; support 960H HDMI resolution
*960H is a 34% increase over standard D1 resolution and a 500% increase over CIF
*USB backup, upgrade and mouse *operation
*PTZ Control
*Motion detection with instant email alerts
*Supports Remote View via smartphone & 3G Mobile with each of those systems below: WindowsTM XP, Mac, Vista, 7 , 8, iPad , iPhone, Android

Camera Feature
GW400WHD: 1/3" Color SONY CMOS Outdoor/Indoor Camera, 1000 TV lines, 2.8~12mm Manual Varifocal Lens, Metal vandal proof & water proof
*High Resolution: 1000 TV line (720P Analog)
*Built in 2.8~12mm Manual Zoom Varifocal Lens which allow you to adjust the angle of View
*64PCS IR LED, up to 147 feet IR distance for night vision
*OSD menu and Digitally zoom in the frame with Button Control, Outdoor/Indoor waterproof

Package Includes
1 x GW9314AHD: 4 Channel DVR with Pre-installed 1TB Hard Drive
4 x GW400WHD: 1000TVL Varifocal Camera
1 x GW150CAB : 150ft Pre-made BNC Cable
3 x GW50CAB : 50ft Pre-made BNC Cable
1 x GW12V2A: Power Supply for Cameras
1 x GW124CA: 1 to 4 Power Splitter Adapter Cable