Combination 2400mA USB charger and 3-LED battery monitor with vehicle battery protection. - Vehicle battery protection: USB output turns off 3 hours after engine stopped or when vehicle battery charge level is less than 50% - 3 LED battery monitor (when USB output off) - battery status is displayed every 5 seconds - 12V input through an industry standard SAE 2-pin connector - 5V 2400mA true output - Unique seal and cap design for USB socket use any USB cable seals when inserted - Short circuit overheat over-voltage protection Universal