Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: GW Security 16 Channel 4K NVR HDMI H.265 Security Network Video Recorder - Supports Up 16 X 4K 8MP /5MP /4MP /3MP 1080P Any ONVIF IP Cameras @ 30fps Realtime, Quick QR Code Smartphone Access, 3TB HDD
Product description: 16-Channel 8MP 4K (3840x2160) NVR - Supports Up to 16TB HDD + 8 x 4K 8MP/5MP/4MP/3MP /2MP 1080P IP Cameras / Easy QR Code Smartphone Access / Access via software or web-browsers on MAC & PC / VGA & HDMI Output / ONVIF Compliant / Backup to External Storage via USB This NVR works with virtually any ONVIF compatible IP camera and after a quick and painless plug-and-play setup process, you can remotely watch things happen as they happen: real-time, highly reliable HD video without loss or delay, transmitted anywhere you have a wireless signal. A new cornerstone in the consumer market for private security technologies and an unsurpassed value with GW Security's 1 Year Warranty and Free Life Time Tech Support, each NVR is further enhanced by DIY installation and the plethora of features outlined below. Features: - Superb Video Quality and Clarity: Support up to 4K 8MP/5MP/4MP/3MP/2MP 1080p @ 30fps Realtime each channel - 2 USB3.0 ports, 2 SATA2.0 HDD port(up to 8TB each, total 16TB) - Record in Widescreen, Quick Access QR Code Remote Viewing on iPhone, iPad, and Android (w/ included Free app) - Remotely Access Using Windows and Mac Browsers (IE/Chrome/Firefox/Safari) - H.265 & H.264 compression technology, support VGA and HDMI output (up to 4K) - Support the video file by time queries, according to the precise time position for video playback - Easy to Install: Connect to and Manage All Cameras on Your Network Wirelessly - Feature-Rich OSD: Camera Name, Time, Motion Detection, Video Loss, Lock, and Record Status Icons - Multiple Trigger/Alarm Events: Recording, PTZ, Tour, Video Push, Email, FTP, and Buzzer - Custom Record Modes (e.g. Manual, Scheduled, Motion Detection) and Record Intervals (1-120min) - USB Backup Feature for Peace of Mind Include: GW3216E: 16-Channel NVR with 3TB Hard Drive Pre-installed USB Mouse Power Supply User Manual 1 Year Warranty and Free Tech Support
Product feature: 16-Channel NVR Supports Up to 4K 8MP/5MP/4MP/3MP/2MP resolution realtime preview&playback, 4K/1920P/1440P/1536P/1080p @ 30fps Realtime each CH, Supports Motion Detection & Email Alerts & USB backup, VGA and HDMI (Maximum 4K HD 3840 x 2160) output, Plug & Play setup, Easy to configure, access and control. Scan QR Code on NVR from Free app to instantly access live viewing and playback for your iPhone, Android, PC, Mac, iPad, and Tablets, Supports up to 16 virtually any ONVIF compliant IP cameras (H.265 & H.264 Compatible), It comes with 3TB Hard Drive Pre-installed and 1 Year Warranty and Free Life Time Tech Support From U.S.A.
Product price: $479.00
Product brand: GW Security Inc
Target attributes: Number of Channels
Answer: attribute: number of channels
value: 16-channel
source: product feature
attribute: number of channels
value: 16 channel
source: product title
attribute: number of channels
value: 16-channel
source: product description