WET Sensor Kit WET-2-K4 Comprises WET-2/d

Specific substrate calibrations : This version comes with built-in calibrations for artificial growing media, making it ideal for use in hydroponics and with substrates like coir, peat, and mineral wool. 
Data logging : The HH2 meter can store up to 1,000 readings, which can then be transferred to a PC for analysis. 

Get more information on WET Sensor Manual and Data sheet