1. The working time and capacity display has a memory function after power off.2. Press the RTZ reset button for 3 seconds and the screen display will be reset.3. USB intelligently monitors current and voltage capacity.4. Portability: This product is small in size, light in weight, and convenient to carry.5. Good quality: This product is made of high-quality materials, exquisite workmanship, good quality and long service life.It can also help safe charging and monitoring your charging data in real time.Model: KWS-V21Voltage: Input/Output Voltage: 4-20V, Voltage Resolution: 0.01VCurrent: Input/Output Current: 0-3A, Current Resolution: 0.01A temperature: 60 ()Accuracy: 1%Line loss: about 0.1 ohmsColour:transparent blackMaterial:plastic+metalSize:73 x 23 x 13.5mmPackage Contents:1 x USB TesterOnly the above package content, other are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real . The measurement allowed is +/- 1-3cm.