1 Channel 5V Relay Module

Description
The module uses the Songle relay for control, AC voltage max at 250V, AC current max at 10A, DC voltage 30V DC current maximum 10A;
Basically Connecting on high TTL and open or low TTL.
Operating voltage 5V
With fixed bolt hole for easy installation
Power indicator (green), four relay status indicator (red)

Connection:
VCC connect to 5V
GND connect to GND
1N1-1N8 relay control interface connected MCU's IO port
Current version added optical coupler, can select either high or low TTL to trigger relay.

1-Channel 5V Relay Module w/ Opto-isolator
Supports high / low level trigger;
Max. load: AC 250V/10A, DC 30V/10A; SMD opto-isolator,
trigger current: 5mA;
Module working voltage: 5V;
Module size: 50mm x 26mm x18.5mm

*note*: The current batch of these relays of 27/11/2017 - The VCC and GND Pins are swapped due to manufacturer error. The Pinouts for these modules from left to right are the following:
1(N/A) - 2(Trigger) - 3(GND) - 4(VCC)