BlueFire Dual USB 4.2A Charger Adapter and LED Voltmeter Panel Waterproof 12V-24V for Motorcycle Car Boat Marine Carvan Waterproof LED illuminated USB charging socket & Voltmeter Fits for any flat interior and exterior application. 4.2A Dual USB Power Charger, Great for charging your Phones, Tablet, Android Devices, PDA, GPS ect. LED Dynamic Voltmeter Help monitor the storage-battery voltage, LED will alarm flash if the voltage is out of the safety range Universal compatible with 12V-24V Motorbike Car / Boat / ATV / UTV / Camper / Caravans / Travel Trailer etc. Product Dimensions: 10.5cm x 4.3cm x 5.5cm (4.13in x 1.69in x 2.17in), Portiforium Dimension: 7.2cm x 2.9cm(2.83in x 1.14).