Hydrofarm Light Track 

The Hydrofarm Light Track slowly moves your grow light fixture back and forth along its 4-foot length, providing a more even level of brightness throughout the plants. 

Travel time from one end to the other is about 13-1/2 minutes.

The movement of a grow light also helps eliminate shadows between plants to encourage even growth throughout your garden.

The 4' Hydrofarm Light Track provides a simple, yet effective method of operation. Using a Swiss-made motor, the light bracket is chain driven from one end the metal rail to the other. After a slight hesitation, the direction reverses.

All installation hardware is included. We recommend lubricating the inside of the (rail) track grooves every 90 days to maintain smooth operation.

1 year warranty

More info from the Manufacturer (PDF format - Lots of detail.)