When using it, be sure to park the car on a flat ground and apply the handbrake or footbrake tightly. Otherwise, if one wheel lifts up, the other three wheels may move, which could be dangerous. So when using a jack, be sure to park the car on a flat ground and apply the handbrake or footbrake tightly. Note: After lifting the vehicle with a jack, it is essential to support the entire vehicle with the jack bracket. The jack is only used to raise the vehicle body. Sometimes, the jack may release pressure and cannot guarantee your safety.