Hortilux High Pressure Sodium lamps have a high energy spectral output for plant growth. They provide more total energy for plant growth than standard HPS, with an increase in the violet, blue, and green spectrum. Environmentally friendly, and meets US Federal EPA TCLP criteria for non-hazardous waste. Produces 54,000 Lumens and has a Kelvin rating of 2100º. Can burn in the horizontal or vertical position.