Type: Coupling valves, i.e. the integration of distribution valve (slide vale), and hydraulic cylinder(single-stroke reciprocating cylinder). Coefficients: Working pressure: 6.87Mpa; Cylinder: φ40mm Throw of piston:250mm Connecting rod: φ20mm Opening clearance of slide valves:0.2mm(each side) Slide stroke:1mm (each side) Uses :Hydraulic pressure for steering wheel of tractors to move with ease and safety