Solid State Relay - 8 Channel - (Low level trigger)
"Low Level Trigger" SSRs close a circuit on when the input turns off.
So you can have a light on a battery, which turns on when your mains power goes out.
(We will add a diagram soon)
This is a transistor-based switching technology, so there are no moving parts. Optocoupling keeps input and output circuits isolated from each other. They can't handle as much load as the mechanical relays, but use less current to keep the circuit closed.
The module has both ribbon-cable connection, and screw-fastened connection options.