Iztor 12-24V Three Marine Cigarette Lighter Splitter Power Adaptor Sockets Waterproof dustproof material can be used for the interior and exterior application. Widely used with electric equipment for power supply: Vehicle,GPS, mobile phone, camera, mp3 (cannot smoke) Allow any marine or automotive with a cigarette plug attachment to be used with these surface mount cigarette sockets. Rating: 12V-24V,Barrel inner diameter:2.1cm/0.83",Barrel inner length:3.6cm/1.42" Short circuit / overheat protection.include 2 screws and 4 terminal connections