[MULTI-FUNCTIONAL for CHARGER SOCKET] This 45W Dual USB for CHARGER Socket includes a LED voltmeter switch, providing fast charging for mobile phones, tablets, and other USB devices in vehicles, motorcycles, ATVs, SUVs, UTVs, and boats. [REAL-TIME VOLTAGE DISPLAY] The smart for CHARGER features a voltage display that lights up when powered on, allowing you to monitor real-time voltage and charging effortlessly. [USER-FRIENDLY SWITCHING MODES] Easily switch between display modes with a simple press of the button; long-press to turn off power for energy savings when not in use. [SAFETY INDICATOR LIGHT] A red indicator light alerts you when the input voltage exceeds 6V,making sure safe operation and potential damage. [SIZING REMINDER] Please refer to your own size chart for installation requirements rather than Amazon's size chart.