The HPL-550/77V Compact Filament Halogen Lamp (750W/77V/3250K) from Ushio has been redesigned for a more efficient light collection. It's ultra-compact filament geometry now improves the optical efficiency of the ETC Source Four fixtures to produce up to 20% more fixture lumens. That's up to 20% more light from the same fixture as compared to the old lamp design.