5 buttons and a rotary knob/multiple functions on the car stereo to be mapped to them, including voice command, volume control, skip forward/skip backward, hang up/answer, and many more (more than 20 on ATOTO A6 PF, for instance) | Mounting is very easy. Either wrap it around the steering wheel with the watchband, or stick it at a handy location. Convenient and good-looking. Remember to get this product before you install the car stereo to avoid having to take the stereo out of the dashboard for wiring! | Driving is safer, as you can easily control your ATOTO car stereo while staying focused on the road even if there are no original steering wheel key controls available on your vehicle. | All the buttons are made of luminous materials, very helpful for night driving! | This product is compatible with all ATOTO car stereos except the P8 series, and third-party car stereos that support this particular wiring option and key mapping. Besides, if your car stereo is an ATOTO SA102 Starter, A6 (excluding A6 PF), F7, or S8 (excluding S8 Lite), you can also choose ATOTO AC-44F5 wireless control for a plug & play solution. Important: NOT compatible with P8 series.