Ambient Weather WS-3000-X5 Thermo-Hygrometer Wireless Monitor w/ 5 Remote Sensors – Logging, Graphing, Alarming, Radio Controlled Clock Description
There are 8 wireless sensors in this kit. They work together and you can use the software to do advanced things with the data. You can also take data from a microSD card if you choose. The main unit for this kit is 3 x 4 x 1/2 of an inch, but each sensor needs 2 x AA batteries which are not included.