Telescopic Linear Operator

A linear operator for a sliding door comprising:

• a body configured for attachment to a door header;
• a first wheel rotatably attached to the body at a first position on the body;
• an arm movably attached to the body;
• such that the arm is movable telescopically in relation to the body and in a direction parallel or substantially parallel to a longitudinal axis of the body and such that the arm is fixable to the body at a desired telescopic position;
• a second wheel rotatably attached to the arm at a second position on the arm;
• and
• a conveyor extending between the first wheel and the second wheel, movable about the first wheel and the second wheel, and operable for attachment to a door,
• wherein the arm is set to the desired telescopic position based on a desired movement distance of the door when the door is attached to the conveyor, and wherein movement distance of the door varies in direct proportion to distance between the first position and the second position as arranged by the desired telescopic position.