1. The packaging of original accessories is generally standardized, the specifications are unified, and the handwriting is clear and rules. The product name, specification and model, quantity, registered trademark, factory name, address, and telephone number should be indicated. Some manufacturers also make their marks on the accessories.

　　2. On the surface of the parts with a qualified appearance, the printed or cast characters and marks are clear and regular, with certain precision and smoothness. The more important the parts, the higher the precision, and the stricter the rust and anti-corrosion packaging. If it is found that the parts have rust spots or the rubber parts are cracked or lose elasticity, or there are obvious turning tool lines on the surface of the journal, they should be returned for replacement.

　　3 Illegal paint dealers can pretend to be "qualified products" by simply dismantling, assembling, assembling, painting, and other processing waste parts. After removing the surface paint, the old paint can be found.

　　4 The appearance of the product is sometimes good, but due to the poor manufacturing process, it is prone to cracks, blisters, slag inclusions, burrs, or bumps. If the cylinder gasket is squeezed and deformed, it is easy to cause air leakage, air leakage, and water leakage.

　　5 Look for "loose" parts consisting of two or more parts that are formed by pressing, gluing, or welding. Loosening is not allowed.

　　6 Look at the assembly markings. To ensure that the assembly relationship of accessories meets the technical requirements, assembly marks are engraved on the surface of some conventional parts, such as timing gear marks, piston top marks, and other assembly marks to ensure the correct installation of parts. If there is no mark or the mark is blurred, it cannot be recognized, which will bring great difficulties to assembly, and even lead to the wrong assembly.

　　7 Normal assembly parts must be complete and intact to ensure smooth loading and normal operation. Some small parts on the assembly are missing and may be "parallel cargo", which can easily cause loading difficulties. Even entire assemblies can be scrapped due to shortages of individual small parts.

　　8 Look at the protective layer. To facilitate storage and prevent the parts from bumping, the parts have a protective layer before they leave the factory. For example, the piston pin and bearing bush are protected with paraffin; the surface of the piston ring and cylinder liner is coated with anti-rust oil and wrapped with wrapping paper; the valve and piston are immersed in the anti-rust oil and sealed with a plastic bag. If the sealing sleeve is damaged, the wrapping paper is missing, or the anti-rust oil or paraffin is missing, it should be returned for replacement.

　　9 Look at the certificate. Some important car parts moulds, especially carburetors, distributors, generators, and other assemblies, usually have manuals and certificates when leaving the factory to guide users in installation, use, and maintenance.

　　10 Look at the manual. Most auto parts have specific models and technical parameters. When purchasing electrical equipment, you should pay attention to check whether the voltage and power of the replacement car parts mould are consistent.