SolarMaxâ„¢ grow lamps are designed with the grower in mind. As plants approach maturity they require less "Blue Light" and depend more upon radiation from the "Red" portion of the spectrum between 610 nm - 720 nm. SOLARMAX HPS lamps have been engineered to constantly deliver 10% more targeted "Red Light" energy to the maturing plant to promote aggressive flowering. High Quality for optimal performance Designed with the grower in mind Works with both magnetic and digital ballasts Reduced lamp sizes to fit most horticultural lighting fixtures Custom tailored spectral distribution ensuring the highest PAR output All SolarMAX lamps carry a full ONE YEAR MANUFACTURER'S WARRANTY Made in Germany