①.Professional guidance needed for installation. Wrong installation will cause short circuit.②.This is an electric touch screen radio, not a capacitive screen. Please use your nails to slide the screen.③car stereo bluetooth applies to a power supply voltage at 12V DC, short circuit will happen when applied to different car voltage.④.Pls don't change the fuse in the power cord without professional guidance;improper fuse may cause damage to this using unit or even cause fire.⑤.Never expose the unit,anplifier,speakers to moisture or water to prevent electronic sparks or fires.