Comparison of 821 series DX、DT controller module

	821-DX	821-VD（4G）	821-VD

	821-DX	821-VD（4G）	821-VD

Camera	DC7121, Digital camera		CMR7121, Analog camera
Camera angle	Horizontal angle 160 degrees		Horizontal angle 130 degrees
Lens	Null		Yes
Hidden Settings Keys	2pcs, TK-A,TK-B		2pcs, TK-A,TK-B
Indicator LED	Indicated by the action of the LED（Off,on,flush)		Indicated by a icon corresponding to the LED
Night vision light	Warm color LED		Cool color LED
DIP	Null		6 DIP
Port-LAN	Networking mode 1, non-power supply interface		Null
Port-Lock	1 lock + exit button		1 lock + exit button
Built-in Wi-Fi	Networking mode 2		Null
Built-in 4G	Null	Yes	Null
Clock	Yes, built-in battery, supports clock		Null
Adaptation module	M4,MK,DR		All modulars of 821 series
Dimensions	83.8mm(H)*100.5mm(W)
Port-BUS	2P ( L1,L2)