*Stabilizer for the Power-Saving Metal-Hallide Lamp (PSB: Power Saving & Safety Ballast). Efficiency of the stabilizer is HM 150WI 220NB: over 93%, HM 200WI 220NB and HM 350WI 220NB: over 95% This stabilizer have removable power saving ignitor (PSI) installed, that prevent the idle and 2nd short circuit, prevention of miss running of SCR . It limits the standby power and prevents an electric shock and the fire from blast. You will experience no flickering with this device and it is power-saving, safe, high efficiency. All three types are all certified as high efficiency, power-saving item by Energy Management Corporation.