For effective growth and health of plants, light is essential at every stage of development. If plants don't get enough light they become weak and may even die. Even light emitted by windows may not be enough to the plant and the best solution is to grow the seedlings under LED or fluorescent grow lights. LEOTER 4 Head Led Grow Light with TIMER hastens growth of indoor plants. 1. Red Light: 660 nm is the peak wavelength for photosynthesis and photoperiodism. Red light is best for blooming and fruits. 2. Blue Light: Blue light is good for photosynthesis; and help to induce chlorophyll and carotenoid, which are necessary for nealthy leaves. A mix of red and blue provides the light that plants need to grow. 3.Warm White(Sunlike Full Spectrum): Warm White light(380-800nm), sunlike full spectrum, contains other auxiliary light besides red and blue light, which plays an important auxiliary role in the growth of pants. Suitable for all plants to root and sprout. A mix of red+blue+Warm White is best to fuel the growth of your plants. NOTE: 1.Please don't look at the grow light when operating. 2.Would be better to keep the distance between the light and plant in 20-30cm. 3.Generally this grow light should be turned on for 8-12 hours every day. SPECIFICATION: Product Size: 11.8 * 5.1 * 3.1 inches Product Weight: 2.2 lbs LED Chips/Bulb: 36 Red(620-660nm), 16 Blue(460-470nm), 28 Warm White(380-800nm) Material: PVC Power: Max 40W Input voltage: 5V Life time: 50000 hours Timing setting： 3H/9H/12H (Blue means timer of 3 hours, green 9 hours and red 12 hours.) PACKAGE INCLUDED: 1 x 4-Head LED Grow Light 1 x USB Charger 1 x User Manual  * All products we sell can be exchanged or refunded within 1 year of purchase. If you have any problems, please feel free to contact us.