SongHe 1 Channel DC 3V Relay High Level Driver Module Optocoupler Relay Module Isolated Drive Control Board for Arduino (Pack of 5)

Can be used from a ESP32 system which has 3.3V logic without any additional circuitry. Has screw terminal blocks for both sides of the relay making it easy to integrate with microcontroller board. Has a red LED that lights when the relay is activated, giving good operational feedback. Only niggle is that the screw holes are a bit small. i had to enlarge them with a file to fit normal sized standoff screws.

They come attached, but are easy to split off individually if needed. They’re working great, controlled by simple GPIO pins from an ESP32 board.

Works as expected. Well made. The only problem it's five of them, I only needed one - what a waist.

Awsome little rely boards. I am using them with an ESP32 and they are switching 24 VAC for zone valves and to trigger my boiler's circulator pump and burner. My only complaint is the screw holes are too small and very close to the terminal blocks, however, they still deserve 5 stars. Some have mentioned issues powering these. They are happiest receiving 5 volts to the VCC pin and ground and they have no issues with the 3.3 volt signal from the esp32. Just something to keep in mind when using these. I have a buck converter that reduces the 24 Volts AC to 5 volts DC with a 2 Amp capacity. I am running 10 sensors, 2 ESP32s, a SSR and 5 of these relays off a single converter so power draw isn't an issue. The boards are well made and the components are mounted very well. The indicator LED is nice to have and the relays have a solid and satisfying click when they are engaged.

I decided to build a custom pool pump controller using a Pi Pico W and needed something to use for physical interface. This works perfectly using the Pico's 3.3v source and driving the relays from the GPIO pins. Of the five relays, I'm using four to switch 28 VAC to control a variable speed pump and to open/close a water valve. The fifth relay is switching 240 VAC for the axillary pump. It may or may not be the relays' fault, but I found that switching relays sometimes caused noise problems on the wire I had connected to the Pico's reset pin, so beware of that kind of thing.