This Prius Accessory adds an automatic door lock feature for added comfort and safety. This is typically a common feature in most cars, but is not in the Prius. The plug-in kit signals the doors to automatically lock when the car accelerates past 15 mph. It performs this function only once when the car is initially driven and remains invisible the rest of the time. It does not interfere with the remote control, door switches or automatic entry and is designed to seamlessly add this safety feature to the normal enjoyment of your car. As always, complete instructions with color photos are provided and no wires are cut or soldered.