METER Group SOLYX 14. Root-zone water content, EC and temperature, for the Grow Sensor PRO.A third-party SDI-12 substrate probe using METER CDX (complex dielectric) measurement. It reads volumetric water content, bulk EC, pore water EC and temperature in soil and soilless media. Plug it into the Grow Sensor PRO through the RJ12 connector block. One probe at a time.Buy it on its own if you already have a Grow Sensor. Or choose it as the probe in the complete system instead of SubSense.Measures Volumetric water content (VWC) Bulk electrical conductivity and pore water EC Substrate temperature Tech specs Output: SDI-12 or DDI-serial VWC: 0.00–0.72 m³/m³ mineral calibration, ±0.03 generic / ±0.01 medium-specific Bulk EC: 0–20 dS/m Temperature: −40 to +60 °C, ±0.3 °C from 0 to 60 °C Needles: 5.5 cm stainless steel Body: 8.9 × 2.5 × 7.5 cm, IP65 / IP67 Cable: 5 m standard Power: 4.0–15.0 V DC Requires a Grow Sensor PRO and the RJ12 connector block (included in the complete system, sold separately otherwise).