★One-time molding, a hard protective layer is produced on the surface, which is anti-oxidation, wear-resistant and durable, and improves the service life of the product ★Hard oxidation treatment, with super anti-oxidation ability, not easy to aging ★The material is thicker, which improves the stability of the cylinder and has stronger impact resistance ★It is more durable and more concentric with hard chrome plating and grinding treatment ★If you encounter a problem during the purchase process, you can contact by email, and we will reply and solve it for you within 8 hours, Manufacturer: GQNBLVHZUPDM