Elevator door operator: 1\In fulfillment with GB7588-2003, EN812\Totally reliable, towed truck with unique security device3\Top and bottom roller using material P66, durability and low noise4\Steel rope with spring for self-tightening5\Rational structure, assimilating series of foreign door lock6\Applicable for all types of door panel, easy connection For more information and details,pls contact me without any hesitation.