For a rectangular growing area, a linear lamp moving system is preferable. The self propelled Light Rail 3.5 Intelli Drive is without question, the finest linear lamp-mover available. It uses no pulleys, chains or gears. Simply mount the standard 6 foot track over the desired area and place the lamp-moving drive motor onto the track. The Light Rail 3.5 Intelli Drive is supplied with adjustable switch stops, so lamp travel can be any length you wish. This is perfect for a start-up size garden to a full growth garden. The standard 6 foot track may also be extended. Light Rail 3.5 comes with a 2 Year Factory Warranty. Extension not included.