The newest technology in High Pressure Sodium are the Double Ended HPS bulbs. These bulbs degrade slower than traditional single ended HPS bulbs. In fact, after 10,000 hours double ended lamps will still output approximately 90% of their original intensity. Double Ended HPS bulbs are also more stable than traditional single ended HPS bulbs, and this allows them to have a 10% increase in light intensity and PAR output over traditional single ended HPS bulbs. Lastly, Double Ended HPS bulbs emit more UV and IR light than traditional single ended HPS bulbs, increasing the potency and essential oils of oil producing plants. View Growers House Review Lab test of 1000w Double Ended bulbs compared to traditional 1000w HPS bulbs.