4pcs DC 5V Relay Module - 1 Channel Relay Switch Board with Optocoupler Isolation, High or Low Level Trigger

Seems to work with 3v logic level. Had some trouble with the inverse logic jumper. Looks like it floats and you need to use a pull-down resistor. When I did that 3v triggering stopped working though, so maybe the 5v rating refers to inverse logic mode?

Works are expected. Happy with the performance.

Once of these modules was intermittently closing the relay with a 4.5V source, fully capable of 300mA+. Sometimes it wouldn't close, and the relay would need to be physically tapped for it to actually close. I measured the current to that whole module at 81mA when closed. Yes, that's not the full 5V, but I found it worrying. I replaced it with another module and the replacement was able to consistently close with a voltage all the way down to 3.8V. The draw on that module was 95mA. So these have a large variance in tolerance. You may want to test each module to see if it can handle small voltage sags.

Works fine for dev purposes. The terminal blocks are poor, and don't accommodate larger gauge wires. Max is probably 16ga. stranded, since the 14 ga. stranded doesn't fit each strand very well. I also don't like the Phillips screw heads, as most other terminal blocks have slotted. That means more tools on the workbench, which is annoying.

Worked as intended