This pulse start 450W Elliptical Metal Halide light bulb produces 45,000 lumens of crisp natural white light, and is perfect for applications such as outdoor lighting of squares, parks, roads and car parks. Fitted with a GES-E40 Goliath Edison screw (40mm) cap (sometimes known as a giant screw cap).This light bulb is designed to operate on pulse start ballasts with sockets that can withstand a 4000 volt pulse. The substitution of standard (non-pulse start) metal halides will result in poor performance and is not recommended.For full technical specification sheets, please refer to the manufacturers website here.