Sierra Arctic 12V Dc Voltmeter 68383P2 in. gauge displays engine alternator output in volts. Arctic 12V DC Voltmeter 8-18 volt DC range 2 in. diameter Ideal for outboards and stern drives Arctic series White face White bezel Black numerals and graduations Scratch-resistant domed glass lens Through-dial and perimeter lighting for excellent readability at night US and metric scales with ISO symbols where appropriate