The size of your window shade determines the motor that will be used. The typical battery operated motors can only handle small window sizes. Larger window shades spanning more than 72" in width and 84" in length require heavy duty motors. Fortunately, there are motors for bigger shades and the quietest and most reliable motors in the industry are Somfy, Rollease, and QMotion. These motors handle shades up to 144" in width and 144" in length (and larger with special order).