1.grow lightEquipped with 20 Red + 100 White LEDs put out enough PPFD and luminosity for growing seeds, light is similar to the full spectrum sunlight at noon,that is professionally designed for indoor garden plants. 2.Auto Turn On / Off Timer:led grow lights bars can be set up to turn off after 3H/ 9H/ 12H. After you set up the hours, you do not need to manually turn off the light or cut off the power supply, the light will automatically turn on at the same time the next day.