Separation type oil pressure jack RRH double acting piston Jack used extremely widely used in machining, maintenance, traction operation, special hollow piston design enable traction stem or cable can work through the jack, in a variety of platen and mechanical traction system, commonly used in backward traction and forward extrusion of homework Characteristic Part of the piston rod in welding copper, surface hard chromium plating, never cylinder, abrasion resistance Hollow piston design can be pushed and pulled by force Spring reset structure, outer ring thread to make the installation more convenient