IZTOSS 12/24V Marine Boat Caravan Car Cigarette Power Socket + LED Digital Display Voltmeter Socket Include 4 X Connector Terminal,4 X Screw,short lines Short circuit / overheat protection,2 pole protected terminal connections. Can be installed vertically, horizontally or underneath the dash, or any flat surface. Barrel inner diameter:2.1cm/0.83",Rating: 12V -24V Barrel inner length:3.6cm/1.42"