This Replacement for GE MPR400/C/VBU/O/40 is a 400W metal halide HID lamp built for dependable, high-output performance in commercial and industrial lighting fixtures. It features an E40 base and ED37 white coated bulb with an 11.5" length for proper fit in compatible systems using an M59 ballast. Designed for bright white illumination, this lamp provides consistent, high-quality light ideal for warehouses, gymnasiums, outdoor areas, and large workspaces. It is rated for use in both open and enclosed fixtures for added installation flexibility. With a rated life of up to 20,000 hours, this HID lamp offers long-lasting performance and reduced maintenance in demanding lighting applications.