A. This air filter features a unique cylindrical design that adheres to aerodynamic principles, effectively enhancing air filtration efficiency. It is specifically designed for off - road motorcycles, all - terrain four - wheel ATVs, etc., and is suitable for models with a displacement of 50 - 250CC, providing reliable protection for vehicle engines. B. The product offers a variety of specifications, including 35mm, 38 - 40mm, 42mm, 44 - 46mm, 48 - 50mm, 52 - 58mm, 58 - 60mm, etc., which can meet the specific needs of different models. There are also multiple options for connection threads, seal ring sizes, inner diameters, etc., facilitating users to make adaptations according to actual situations. C. Whether driving on a dusty off - road track or in complex environments such as beaches, this air filter can accurately filter impurities and dust in the air, ensuring that the engine takes in clean air. D. As a result, it can improve the performance and service life of the engine, making your off - road journey smoother and safer.