High Pressure Sodium Horticulture Bulb. This 400w Super HPS grow light allows you to stretch your growing season to 365 days a year. Recommended for flowering / fruit bearing plants. The HPS Horticulture Bulb provides 15% more energy for plant growth than the standard high pressure sodium bulb plus an optimised spectrum! Lumen: 58,000, Color Temp : 2100 Kelvin, Tubular Shape, fits E40 Socket.