Current meter display 5A Red Header :4-30V operating voltage supply ( wiring diagram look at the bottom ) , there are reverse polarity protection , reverse polarity will not burn Measuring current range :0-5A DC current The machine power consumption : <= 20MA, very low power Refresh rate: 3 times / S Test Accuracy: 0.1% +2 word ( precision ) Display colors: red Digital tube size : 22.5 * 14.1mm (0.36 inch three integrated digital control ) aperture openings 27MM 2.5MM pitch