Charger 5V / 4.2A Dual USB Car Charger Two USB charging ports with a single 2.1A output allow you to charge 2 devices at high speed simultaneously. Protection 10A fuse protection, Built-in 10A fuse protects your devices from overheating, overcurrent, over voltage, over voltage, under voltage and short circuit. Wide application fits Universally suitable for vehicles, boats and pleasure craft, motorcycle, truck, SUV, UTV, etc, powered by car and you can also use the connectors we offer for higher load capacity . Easy installation, The hole diameter is 3cm. " + " at the positive pole, " - " at the negative pole. A tight cap protects the USB ports when not in use. Also, it can be wired to an on / off switch, then you can turn it off if it is off to save power. Waterproof and heat resistant, With waterproof cover and does a good job in high temperature and low temperature (-20 C to 60 C) environment, hard durable flame resistant, resistant to strong currents , high temperatures and wear. Product description Color: Dual USB Charger Features: 1. Wide Compatibility, not only suitable for 12-24V DC cars, but also provides perfect performance on boat, marine, motorcycle, 4 wheeler, RV, etc. 2. MultiProtect security system, RoHS, CE and FCC certified. Surge protection, surge protection and more advanced security features keep all your devices safe. 3. Real-time monitoring voltage, automatically monitors the vehicle's battery and electrical system in real time, and shows the voltage on the screen How to install? 1. Drill a hole approximately 1.13 inches in diameter using a hole opener. 2. Place the USB charger in the hole. 3. Screw it tight. How to connect? The rear terminals are identified by the symbols " + " and " - " for the positive and negative poles. Package includes: 1x dual USB port charger 1x wire with 10A fuse