Review on 🌡️ Weewooday 6-Piece W1209 Micro Digital Thermostat Temperature Controller Board with Case, 12V DC -50-110°C Electronic Temp Control Module Switch with Waterproof NTC Probe by David Garnic

[Updated 2021-02-28] Uses it for heating in greenhouses (see photo) including inserting the probe into the ground. Excellent. [Original from 09/29/2020] I was looking for something inexpensive for a potential winter protection plant. These 6 packs are more than I need, but it's nice to have backups. Assembling the case took about 10 minutes between removing the covers and fumbling with the tiny screws. Enough to keep my coffee cold. But it's a one-time thing, and the case is actually pretty good. I then ran some quick tests on the main functions. They came with no instructions, by the way, but thanks to Google they're not that difficult to find, although some can be confusing. I changed P0 to "H" (heating) at 27°C with the offset (P1) set to 1°C. After warming the probe up by hand and then cooling it down, I expected the relay to turn on at 27°C and then turn off at 28 (27+1) after being powered by the "heater" aka my hand, was reheated. Instead, it turned on at 26 (27-1) and then turned off at 27. So you need to think of the set temperature as the target at which the device (in this case the heater) will turn off. In other words, it works, just a little differently than I expected, as did some of the "docs" I've seen. So it would be very helpful if the seller would post a document that actually reflects how *this* product works. Another thing I noticed was that the product photos led me to believe the relays are rated for 20A at 125V. It's actually 10A, which isn't a practical issue as I have no known need for have great current. But just something to be aware of. All in all I think it's great value for money and looking forward to warming up some plants this winter!