TDS Meter, Professional-Grade Water Test Kit, Tests Water Quality in Drinking Water, Spa, Water Purifier, 100% Accurate 3 in 1 TDS, EC and Temperature Meter, Best Water TDS Meter for 2018 22 AWG / Gauge / Ga 3 Conductor (each conductor tinned solid copper wire, individually jacketed, and color coded) Unshielded - Gray PVC Jacket Rated for Temperatures up to 75 Celsius (i.e. 167 Fahrenheit) CL2 UL Rating (i.e. rated for in-wall installations in residential class buildings, for up to 150 volts)