The General Tools CO502 Pocket Conductivity Meter is used for determining the electric conductivity for a solution; useful for applications in pool maintenance, hydroponics and aquariums. The meter features a digital display for easier readouts. Instrument automatically accounts for temperature compensation. Pocket-sized and lightweight make this an unassuming tool with many applications. Both CE and RoHS approved; runs on 9V battery which is included. Hard carrying case, calibration solution, and calibration screwdriver also included.