SMAKN&reg; RED Led 0.28" Mini 2 Wire Dc Voltmeter 2.7~30v Digital Display Voltmeter Gauge LED Voltage Detector Measuring range:DC 2.7~30V two-wire access Mounting holes distance:29mm Measurement accuracy:1 %(+/- 1 digit) Display:Three 0.28 " LED digital tube Cutting size:23.5mm x 10mm