Dual Channel Active Low Relay Board
Control AC devices with 0-5 volt signals !

This listing is for a dual channel active-low relay board.  The video above gives you a full demonstration of how it works!  It requires a power supply of 5 volts.  Each relay activates when the relative input line is drive low (0v), hence "Active-low".  There are four input pins:
VCC - 5v Supply Line
GND - DC Ground
IN1 - Input#1: Acts to control relay#1
IN2 - Input#2: Acts to control relay#2

There is an output terminal block for each relay, but these ports are labelled in Chinese.  I talk about the pin out of the relay terminal blocks in the video.  The relays are SPDT, so each of the relays has a common pin, a normally connected pin, and a normally open pin.  If you have any questions, please do not hesitate to ask.  Please see below for specifications =)  

Specification:
Supply Voltage: 5v
Height: 17mm
Length/Width: 45mm
Relay Contact Ratings: 10A @ 250VAC / 10A @ 30VDC