Video/Audio Input HIKVISION 16 CHANNEL DS-7216HQHI-K1  DVR 
Audio Input:   1-ch
Analog and HD-TVI video input:   16-ch,BNC interface (1.0Vp-p, 75 Ω)connection
Supported camera types:   Support HDTVI input: 3MP,1080P/25Hz, 1080P/30Hz,720P/25Hz, 720P/30Hz, 720P/50Hz, 720P/60Hz,
Support AHD input: 1080P/25Hz, 1080P/30Hz, 720P/25Hz, 720P/30Hz
Support CVI input: 1080P/25Hz, 1080P/30Hz, 720P/25Hz, 720P/30Hz
Support CVBS input
Video Input Interface:   BNC (1.0 Vp-p, 75Ω)
Audio Compression:   G.711u
Audio Input Interface:   RCA (2.0 Vp-p, 1 kΩ)
Two-way Audio:   1-ch, RCA (2.0 Vp-p, 1 KΩ), (using the 1st channel of audio input)
Video/Audio Output
CVBS Output:   1-ch,BNC(1.0Vp-p,75Ω),resolution:PAL:704x576,NTSC:704x480
Frame Rate:   Main stream:
When 1080p Lite mode not enabled: 
For 3 MP stream access: 3 MP/1080p/720p/VGA/WD1/4CIF/CIF@15fps
For 1080p stream access: 1080p/720p@15fps; VGA/WD1/4CIF/CIF@25fps (P)/30fps (N)
For 720p stream access: 720p/VGA/WD1/4CIF/CIF@25fps (P)/30fps (N)
When 1080p Lite mode enabled: 
3 MP@15fps
1080p lite/720p lite/VGA/WD1/4CIF/CIF@25fps (P)/30fps (N)
Sub-stream: 
WD1/4CIF@12fps; CIF@25fps (P)/30fps (N)
Video Bit Rate:   32 Kbps-6 Mbps
Stream Type:   Video/Video&Audio
Two-way Audio:   1-ch, RCA (2.0 Vp-p, 1 kΩ) (using the audio input)
Audio Output:   1-ch RCA(Linear, 1kΩ)
Audio Bit Rate:   64kbps
Dual Stream:   Support
Playback Resolution:   3 MP/1080p/720p/VGA/WD1/4CIF/CIF
Synchronous Playback:   16-ch
Network management
Remote connections:   128
Network protocols:   TCP/IP, PPPoE, DHCP, Hik-Connect, DNS, DDNS, NTP, SADP, NFS, iSCSI, UPnP™, HTTPS, ONVIF
Hard Disk Driver
Interface Type:   1 SATA Interface
Capacity:   Up to 6 TB capacity for each disk
External Interface
Network Interface:   1; 10M / 100M / 1000M self-adaptive Ethernet interface
USB Interface:   1 USB 2.0 Interface & 1 USB 3.0 Interface
Serial Interface:   1; standard RS-485 serial interface, half-duplex
General
Power Supply:   12 VDC
Consumption:   ≤ 25W(without hard disks)
Working Temperature:   -10 ºC to +55 ºC (14 ºF to 131 ºF)
Working Humidity:   10% to 90%
Dimensions:   315 × 242 × 45 mm (12.4 × 9.5 × 1.8 inch)
Weight:   ≤ 2 kg (4.4 lb)