All of the LUMii ballasts are compact and quiet running, whilst being reliable and using quality components. This ballast is produced in a fire resistant housing and features a 1 metre mains lead along with a flying IEC lead for added safety. It is cool running due to the use of digital pulse ignition. Other ballasts on the market claim that they are 400 watt or 600 watt, but when tested they produce less power. Some brands cut costs by using inferior components or by reducing the amount of copper in the windings, resulting in less power and less lighting output along with smaller yields. When using a LUMii ballast, you can rest assured that the power stated is what you will get - no corners cut. If you want flexibility then choose the LUMii Dual Core Ballast as it offers dual power levels of 600 watt down to 400 watt. Built to the same standards as the LUMii 400 watt and the LUMii 600 watt ballasts, it gives you two ballasts in one! Always use the correct wattage of lamp to the power selected. A 400 watt lamp running at 400 watt will offer better spectral output than a 600 watt lamp at reduced power.