ACCURATE AND RELIABLE: To achieve high accuracy, equipped with premium quality titanium alloy probe, and reliable Automatic Temperature Compensation (ATC) ensures reading always be accurate at various temperatures. MULTIFUNCTIONAL AND UPGRADED: Professional TDS, EC and Temperature Pen 3 in 1. Upgraded with big backlit LCD for easier reading, and auto-lock function for easier use. EASY AND INSTANTLY: Just turn meter on and stir water gently, then stabilized readings will be auto-locked on LCD in seconds, and the meter will shut off automatically if without operation over 2 minutes. MULTIPURPOSE TESTER: Test the purity of drinking water to ensure it's healthy, monitor if Reverse Osmosis (RO)/DI System works properly, whether filter need replaced, maintenance aquarium, hydroponics(test nutrients), pool and spa, etc.