The 600W Interlux Super HPS Bulb has been tested and developed to work perfectly with electronic ballast. High pressure sodium Super HPS-bulbs are designed specifically for enhancement of indoor plant growth. The 600W Interlux Super HPS Bulb has been tested and developed to work perfectly with electronic ballast. High pressure sodium Super HPS-bulbs are designed specifically for enhancement of indoor plant growth and flowering. With a light spectrum shifted towards the red, thanks to High Pressure Sodium, this lamp is ideal for use during the flowering stages of growth. Features a high lumen output and a wide color spectrum for maximum yield. Standard E39 Base. 1 year warranty.