Relay Module 1Ch 5V with Optocoupler.

Opto-isolated 10A Change-over Relay.
On-board optocoupler circuit withrelay active led indicator.
3-way 0.1" pin header strip for 5Vdc supply and relay operating signal connections - active low.
3-way terminal block connects to relay contacts.
Relay contacts rated at 10A 250Vac/30Vdc.
Relay activation signal is isolated from the relay via the opto isolator.
A separate +ve relay supply can be provided if required via the JD_Vcc pin beneath the jumper link. Ground needs to be tied to the board ground for operation.
Dims - 53mm(l) x 28.5mm(w) x 17mm(h). 4 x 3mm fixing holes.