Features: Multifunctional detection pen, capable of detecting acidity, conductivity, total solubility of solids, salinity, and temperature, meeting different needs. Pocket size, light weight and portable with switchable backlights & large LCD display for clear reading. The electrode probes can replaced with insert type design for convenient and fast replacement. The water test can used to detect water tester tap water, filtered water, and bottle water. Great instrument for any aquariums, the fishing industry, swimming pools, spa, school laboratories, food & beverages, drinking water. Specifications: Component: ABS Size: about 3.99x19cm/1.57x7.48inch Battery: LR44 Number of batteries: 4pcs Working voltages: 6V Operating current: 12mA Conductivity: 0-9990US/cm Package Includes: 1Pc Water Quality analyzers note: Please allow 1-2cm errors due to manual measurement, make surely that you not mind before order. Due to difference between different monitors, the picture may not reflect the actual color.