Our heavy-duty window regulator is calibrated in the factory to hold the specific weight of the window. A variety of springs provide a pretensioning force. You thus need to know how much the window weighs to choose the right weight class. If the sizing is correct, the window will go up almost as fast as it goes down. Incorrect sizing! The window will not lower because the spring tension is too high.

Note:

• The window regulator’s lifting force is significantly greater than the weight of the window. Friction with the window seals is easily overcome and does not need to be taken into account.