This is a splitter to provide another plug for vehicle power adapters, or in "old school" terms, this device will provide two cigarette lighter outlets. In my case, I needed one cigarette-style outlet for a radar detector and another for a car charger plug for my phone. Another option I could have done was to buy a cigarette style plug with USB slots. This would have allowed me to charge up two phones using USB charging cables. Since I already had a car/cigarette style plug for my phone, I didn't see any reason to spend extra money. All in all, this device provides an extra plug that you can customize to your power needs. Plain and simple.