Oakton WD-35462-15 Waterproof EcoTestr TDS High Tester Pocket Meter Push-button calibration capabilities for a wide range of results Automatic Temperature Compensation (ATC) for accurate readings in fluctuating temperatures Transparent, protective cap keeps sensor moist when stored upright, and used as container for sensor conditioning or on-site calibration Large, upright, single-line LCD display screen for ease of viewing, and for display of indicators Waterproof, dustproof housing is Ingress Protection (IP) 67-rated, for protection against solid objects or liquids