These look like an inexpensive display/probe setup...not bad fer $9 shipped. With the red LED display, you'll be able to see it at night just as easily. You can easily wire up a few of these up and git a good idea of yer temperatures...
Digital Red LED F/C Thermometer Temp Auto Car Meter w/ NTC Probe -24 To 125 C | eBay
...or you can go fer a blue display instead fer $1 more.
Digital-Blue-LED-Thermometer-Temperature-Auto-Car-Meter
Looks like it's a dual channel setup...you can hook up a 2nd probe and switch between them to compare readings.
It's a whole lot cheaper than the setup I have...
