When choosing a car heater, generally based on the construction of the parts, I often worry about accidentally buying fake and inferior parts and unsuitable parts. Well. The fonts on the packaging box are clearly visible and the overprint color is bright. The packaging boxes and bags should be marked with the product name, product model, quantity, registered trademark, factory name, factory address, telephone number, etc. Some parts are inconvenient to make, transport, and store, and secondly, they are easy to deform. When testing, you can roll the shaft part along the glass plate to see if there is light leakage at the joint between the original and the glass plate to judge whether it is bent; when purchasing the clutch driven disc steel plate or friction plate, you can use the steel plate and friction plate. Hold the sheet in front of your eyes to observe whether it is warped; when buying an oil seal, the end face of the oil seal with a skeleton should be in a perfect circle, which can fit the plate glass without bending; the outer edge of the non-frame oil seal should be straight, hold it with your hand to deform it, and let go It should be restored to its original state afterwards.