Alwayswish DC Voltmeter Digital and Dual USB Splitter Charger Power Adapter Outlet with Cable for 12V-24V Motorbike Boat Riding Mower Tractor Vehicle GPS Mobile Phone Camera Mp3 DC Voltmeter:A high quality voltmeter for checking the state of your battery and battery charger. Can indicate a poor or bad charging system. Tells whether your battery is holding a charge or not. 2 Port USB Socket Charger: A great quality USB charger very reliable range of 12v power sockets/outlets, Apply to all USB charging mobile phones or other electronic products. Run multiple accessories at one time, very convenient and easy to use. Multifunctional product, perfect for travel use.