GEREE 0.4" Mini Digital Voltmeter DC 1.7-25V with 2 Wires Blue Digital Display Voltage Meter for Car Motorcycle E-bike Three-digit 0.4 " LED dual display, red cable DC+, black cable DC - Quick refresh of about 500 ms. Small size( 4cm X 2cm X1.6cm), DC digital LED display , bright LED, easy to read. Reverse Connect Protection. GEREE Mini Digital Voltmeter warranty--30-Day Money Back Guarantee -- 12 Month Replacement Warranty -- Lifetime Support Guarantee