Spectralux? High Pressure Sodium Single Ended Lamps features high lumen output and 2000? Kelvin color temperature making them ideal for horticultural applications. Fruiting and flowering plants will thrive under these lamps! It can also be used as a full term light source. They are engineered to be compatible with both magnetic and electronic ballasts. Spectralux? lamps are optimized for use with Sun System? brand ballasts and reflectors.