and high quality.Bipolar constant current chopperHigh-speed optocoupler signal isolation inputElectrical input signal is TTL compatibleStationary current is automatically reduced by halfSuitable for any small-and-medium automatic equipment with CNC controller, such as X-Y-Z tables, labeling machines, laser cutters, engraving machines, and pick-place devices.Color:blackMaterial: metalSupply Voltage: 9~42VDCInput voltage: DC 12 ~ 48VOperating Temperature: -10 to 45 Degrees CelsiusStorage temperature: -40 to 70 Degrees CelsiusMax Drive Current: 4AChopping Frequency: 20KHZPackage Contents:5 x 4A TB6600 Stepper Motor Driver ControllerNote: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.