●[NOTE] - The jack piston cannot retract on its own after the pressure is relieved! It must be retracted by gravity pressure on the jack, not a quality issue. ●[IMPORTANT PARAMETERS] - Weight: 30 tonnes | Stroke 1: 0.55 inch | Stroke 2: 0.8 inch | Stroke 3: 0.75 inch | Total Stroke: 2.1 inch| Capacity: 58CC | Self Height: 2.6 inch | Weight: 11 lbs | Compressed Area: 4.8 inch | Inner Diameter 1: 1.18 inch |Inner Diameter 2: 1.8 inch | Inner Diameter 3: 2.5 inch | Outer Diameter 4.1x4.9 inch | Matching Pump: CP-700(not included). ●[IMPORTANT PARTS] -The hydraulic pump consists of ZG 3/8 connector, non-slip handle, hydraulic pump body, release valve and hose. Our hydraulic cylinder jack not only has a smooth surface, but also has good sealing and no oil leakage. At the same time, the non-slip handle makes the use more comfortable. ●[WIDELY APPLICATION] - Widely used in construction sites, petroleum, electric power, metallurgy, chemical industry, ships, bridges, steel and other industries for the installation and maintenance of large and medium-sized machinery and equipment. Not suitable for car. ●[QUALITY ASSURANCE] - Each tool has gone through multiple checks. If there are any questions, please feel free to contact us. Please purchase with confidence.