32" from the light. Led 330w Blue 430-480nm - 26.5 µmoles/m2/s Red 620-680nm- 169.1 µmoles/m2/s Hortiluz Eye MH 400, Lumatek 400 watt Super Lumen Blue 430-480nm - 11.2 µmoles/m2/s Red 620-680nm - 28.1 µmoles/m2/s 600-watt HPS Blue 430-480nm - 10.8 µmoles/m2/s Red 620-680nm - 88.0 µmoles/m2/s