Metal Halide lamps can produce a strong output of the blue spectrum, which will promote strong vegetative growth. This blue spectrum is most needed by plants for rapid growth. Blue light is more beneficial to the healthy development of stems and leaves than to the healthy development of fruits, vegetables, and flowers.It's the best type of light to be used as a primary light source (if little or no natural sunlight is available). If you are growing leafy plants such as lettuce or herbs then a Metal Halide bulb is sufficient.

Metal Halide grow lights can be used as the primary light source to grow plants from start to finish. 

Below is a general guideline on how close to keep the tops of your plants from the bottom of your metal halide indoor grow lights. A good indoor/outdoor garden thermometer will help you dertermine if you can go closer or need to stay farther in your own setup.
 

Application: Greenhouse,Horticultural,Farm,Truck farm,Garden,Arboretum,Orchard and etc.
 

Feature:
High Efficiency;
Long life;
Better color performance and consistency;
Clear bulb finishes.