SMAKN&reg; GREEN 0.40" Waterproof Monitor 12 Volt Battery Meter 2.7-30V DC Auto Gauge Small Digital Voltmeter Dimensions: 50 x 30 x 27mm Measure range: DC 2.5-30.0V Display: three 0.40" LED digital tube Display Color: GREEN Permissible Error: 1% (+ / - 1 digit)