Indoor Sun 600W HPS De 400V Pro HV HV SERIES are lamps which have a voltage as high as 265V, however are known and marketed as 400V. All the Double Ended lamps are HIGH VOLTAGE. They work with lower current (amps) which causes less power loss and lower temperature, resulting in a higher lifespan of the ballast. They provide higher values of PPF & PPF/W than low voltage standard lamps. The HPS PRO HV series is engineered to delivers superior flowering grow light with the HV arc tube inside the traditional bulb shape. The performance is better than standard HPS lamps and close to the HPS DE PRO HV. PPF (Photosynthetic Photon Flux) is the rate of photosynthesis determined by the small light particles called “Photons”. The unit is micro mole per second. Plants have a completely different sensitivity for colours of light than the human eye (PPF is a measurement of plants’ sensitivity). Plants require PPF to grow, especially in the flowering stage. Therefore a higher PPF value indicates more light will be absorbed by the plant. INDOOR SUN PPF = 1200 UMOLE/SEC Go to the Indoorsun lighting website for further details inc specs and test reports POWER 600W 800W 1000W PRODUCT CODE M2350 M2355 M2360 COLOUR TEMP. (?K) 2000 2000 2000 MAX. PPF (µmol/s) 1200 1620 2220 MAX. PPF EFFICACY (µmol/s/w) 1.79 1.84 1.92 LIFESPAN HOURS 10,000 10,000 10,000 CRI % 28 35 35 LUMENS 95000 125000 160000