The 630W CMH grow light has a high efficiency electronic ballast with no acoustic resonance.  The 630w CMH grow light uses a high temperature, resin-sealed componenet board for completely silent operation with a fan.  Each unit is burned-in at the factory for approximately twelve hours to ensure maximum reliability.

The improved, broader spectrum is achieved with the Veg 4200K lamp.  This grow light fixture is used Greenhouse and Warehouse applications.