Specifications YM-2006 The YM mounts to the wall while the wands are always immersed in your hydroponics reservoir for constant readouts. This meter features three screens that read 1. pH from 0-14, 2. TDS from 0-9990 PPM, 3. EC from 0.00-19.99EC, 4. CF from 0.0-199CF, 5. and water temp from -58-158 degrees F, 6. -50-70 degrees C, The YM provides excellent reliability and is the only one with a temperature( degrees F. degrees C ) TDS EC CF function.