The Ultra Sun? 1000 High Pressure Sodium (HPS) DE lamp has a Kelvin temperature of 2,000?K. This lamp emits light in the orange and red spectrum which is ideal for the fruiting and flowering stages of plant growth. It is also an excellent lamp for full term plant growth. This lamp has a high output of 1,985 ?mol and is specifically designed for high frequency DE ballasts. It has a connection at each end of the lamp, removing the need for a frame inside. The absence of the frame eliminates shadows in the beam. For horizontal burning only. The jacket of this lamp is made from quartz glass. Oil from your hands can damage this lamp.