Electro tester with current measurement based on the OpenJaw principle. The electro tester allows for the measurement of voltage, resistance, and current, as well as continuity testing, all with a single compact device. With the T5, you only need to select the measurement function for voltage, resistance, or current—the tester takes care of the rest. The current measurement with a fixed jaw, also known as the OpenJaw principle, enables the measurement of currents up to 100 A without interrupting the circuit. The robust test leads can be neatly stored on the back of the tester, making it easy to carry the T5 in your tool bag. The removable SlimReach test probes are compliant with national electronic standards. The test leads are compatible with additional accessories such as test clamps and specialized test probes. The optional H5 holster is designed to attach the T5 to your tool belt. The T5 is also available as a 600-volt model. Key features.