GEREE 0.28" Dual LED Display Accurate Voltmeter Ammeter DC4.5-30V 10A Voltage Current Meter 2 in 1 Digital Multimeter Three-digit 0.28 " LED dual display, red display for power supply, Yellow for current input, black for COM, common measuring . Meassure range is DC4.5-30V/0-10A, can be calibrated. Ground wire of testing end and power supply temninal is the same wire; quick refresh of about 500 ms. Operating humidity1080%Operating temperature-10+65working air pressure80106kPa. GEREE Dual LED Display Voltmeter warranty--30-Day Money Back Guarantee -- 12 Month Replacement Warranty -- Lifetime Support Guarantee