The new Pro Grow HPS 400W & 620W 6K single ended lamps exceed the output of even the best European branded lamps. All Pro Grow lamps offer up-rated component specifically tuned for use with high-frequency digital ballasts. Improves include monilithic arc tube construction, more robust frame wire material, extruded ceramic ark tubes (not molded) decreased frame wire thickness (for reduced shadow print) and low iron glass for enhanced UV penetration.
Pro Grow 2k is primarily for your flower stage
Prow Grow 4k range covers both the grow and the flower stage
Prow Grow 6k is Primarily for your grow stage