17.5W Highest Efficient Hydroponic LED Plant Growing Lights, Garden Greenhouse in Best Growing Combination (647nm and 450nm, Blue&Red), E26, Par38 (Par38 17.5W)-Short SALE!!! Highest efficiency professional plant grow lights. 50% more lights than 12W!!! This led grow bulb has low power consumptionhigh luminous efficiency and long service life, the electronics inside are stepping down the voltage. the outside is constructed in a pure heat-sink fashion, It does not generate any noticeable heat even 17hrs a day. keeping your temperatures down perfectly. Ultra bright. Really helps when the plant need extra boost of light, or a few of sun, raining, snowing , dark indoor etc. These growing lamps emit the wavelength of light which can be fully absorbed by the plants photosynthesis; no energy waste like fluorescent lights etc. 647 and 450nm are respectively 4 peaks of growth spectrum for maximum chlorophyII A and B production. Sources rich in red light are more efficient and beneficial for photosynthesis, best for blooming and fruit .The Chlorophyll and Carotenoid need blue much, good for the photosynthesis, best for promoting the leaf. IP65, E26 base, specially designed for USA market.