Many consumers have a reverse osmosis system and how no idea if it is working properly and efficiently. The RO filters need changed on a regular basis, but how can you tell if the membrane needs to be replaced? The ONLY way is with a TDS Meter. It is ideal for all water purification applications, wastewater regulation, aquaculture, hydroponics, and colloidal silver. Perfect for both domestic or commercial use. Carry one in your pocket or toolbox at all times! The TDS meter enables you to determine just how good or bad your water really is! These testers accurately measure the TDS level in your water. Ideal for testing reverse osmosis membrane performance and determining the need for replacement. We recommend replacing the RO membrane once it tests at 80% rejection or lower.PRODUCT FEATURES: It is ideal for commercial use.Includes a carrying case with belt clip.The TDS meter has a built-in digital thermometerThe TDS meter is Factory Calibrated.The TDS meter is highly efficient and accurate due to its advanced microprocessor technology.Hold Function: Saves measurements for convenient reading and recording.Auto-Off Function: The meter shuts off automatically after 10 minutes of non-use to conserve batteries.Measurement Range: 0-9990 ppm. From 0-999 ppm, the resolution is in increments of 1ppm.Display: Large and easy-to-read LCD screen.Type: Water Testing MeterNumber of Pieces: 1Material: PlasticProduct Height: 16 cmProduct Length: 3.5 cmProduct Width: 2 cmProduct Weight: 50 gramsColor: BeigeSet Includes: 1 piece tester