★One-time molding, a hard protective layer is produced on the surface, which is anti-oxidation, wear-resistant, and improves the service life of the product ★It is more concentric with hard chrome plating and grinding treatment ★The material is thicker, which improves the stability of the cylinder and has impact resistance ★Imported sealing ring + thickened cylinder body, smooth for a long time without jamming, air leakage, wear-resistant and dust-proof ★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: HPHPH