What trailer safety precautions should the trailer pay attention to?

When a car breaks down, a triangle warning sign should be placed at the rear of the car before inspection. If it can't be repaired, it can only be dragged back. It is best to let the after-sales service car of 4S shop or a professional rescue company tow it. Secondly, it is necessary to refer to the precautions about trailers in the car user's manual to remind rescuers. The basic principle is that the towed vehicle should lift its "driving wheel" off the ground. For example, according to the instructions in the car owner's manual: front-wheel drive vehicles should drag two front wheels off the ground; Rear-wheel drive vehicles should drag both rear wheels off the ground; Four-wheel drive vehicles should tow four wheels or one or two wheels off the ground. Otherwise the transmission will be seriously damaged. Note whether it is manual or automatic: 1) Empty gear. 2) Insert the ignition key and turn it to "ACC" position, and turn off the air conditioner, stereo and other electrical appliances. 3) The parking brake handle must be released. 4) If the vehicle chassis is injured after the collision and cannot walk normally, it is recommended to use flat car traction, which is the safest traction method.