SMAKN&reg; 0.56" 2 Wire RED Dc 3.5-30v Waterproof Automatic adjustment LED Panel Digital Display Voltage Meter Voltmeter Range: DC 3.5-30V ( Can Measure Power Supply Directly ) Power Supply: DC 35-30V (with the input common-line) Display: Three 0.56 " Blue/Green (Option) Resolution: 1% +1 digit; Dimensions: 40x25x23mm;Cutting Size: 36x20mm Waterproof, Dust-proof, Shockproof, Suitable for 6v/12v/24V electromobile and etc.