SeeedStudio Wasserstandsschalter

Great little switch, works perfect letting me know when to refill my garden water reservoir and not let my pump run dry.

This switch is more reliable that the digital switches I've used in the past. It has an instant on-off and it works great! I use it to pump out my dehumidifier.

Great switch, well build. no problem at all using it in my fish tank!

I presume it's a magnet over a reed switch, but no matter. It switches an immersible water pump to control the water level like a sump pump

Easy to use, reliable and cheap