This Replacement for Plusrite 1588 MS350/ED37/PS/BU/4K is a 350W pulse start metal halide HID lamp designed for high-output, reliable performance in commercial and industrial lighting applications. Featuring an E39 mogul base and ED37 bulb design, it installs easily into compatible fixtures using an M131/E ballast system. Delivering approximately 35,200 lumens of 3800K bright white light, this lamp provides strong, clear illumination ideal for warehouses, gymnasiums, retail spaces, and large area lighting. The base-up (BU) operating position ensures proper performance in approved fixtures. With a rated life of up to 20,000 hours, this HID replacement bulb offers long-lasting durability, consistent output, and reduced maintenance for demanding lighting environments.