Disclosed is a brake booster for a vehicle for making an inside of an uniform pressure chamber be a sufficient vacuum and stabilizing the braking characteristics of a vehicle. The cover includes a shell having a first side and a second side and a wireless charging receiver module connectable to the handheld electronic device. The assembled grind rail is of sufficient height, length, and stability to provide a safe and stable riding experience. The number of pixels from which a predetermined color is detected is counted for each sub block. The transmit channel of each SERDES lane is phase-locked with a corresponding receive channel. The output switching control portion selects a group of output portions corresponding to the setting output number among the plurality of output portions based on the one specification shift pulse signal.