Guomao ZLYJ Series Industrial Gearbox | Hardened Helical Gear Reducer for Plastic Extrusion Equipment The Guomao ZLYJ Series Industrial Gearbox is a purpose-built hardened helical gear reducer designed for plastic extrusion equipment and other demanding industrial applications. Developed with a focus on reliable power transmission, smooth operation, and long-term service performance, the ZLYJ Series provides a dependable drive solution for extrusion lines that require