DROK Digital DC 30A Ammeter Panel Amp Meter Gauge +/- Current Tester, AC/DC 8~12V Powered Operating voltage: AC / DC 8 - 12V Measurement rang: DC 0~ 200uA /2mA /20mA /200mA /2A /5A; DC 0~ 10A /20A /30A /50A /100A /200A /300A /500A Version (need an external shunt) Operating current: &lt;15mA; Display: LCD, blue backlight, character height 20mm Dimensions: 79 x 43 x 25 mm; Installation hole: 76 x 39 mm Net weight: about 60g; Measuring rate: 2 times / S; Over-range display: the first shows "1" or "-1"