Sunmaster HPS SL600 U15 2.1K (12/Cs) Proper lighting is a key ingredient in promoting robust, healthy growth as well as meeting the needs of various plant growth phases through optimized spectral outputs. Sunmaster® provides the largest, most comprehensive supply of HID lamps specifically tailored for the hydroponic and horticultural industries. Simply stated, Sunmaster® lamps deliver intense light output with nutriti... This item is sold individually. — Ships from H: WA, CA, CO, MI, TN, PA, FL USA (No USPS)....more info.