This Replacement for Sylvania MS175/PS/BU-ONLY/TF Metalarc is a 175W pulse start metal halide HID lamp designed for dependable, high-output performance in commercial and industrial lighting applications. Featuring an E39 mogul base and BT28 clear glass bulb, it installs easily into compatible fixtures using an M152 ballast system. Delivering approximately 17,500 lumens of 4200K bright white light, this lamp provides strong, consistent illumination ideal for warehouses, retail spaces, gymnasiums, and general area lighting. The clear glass design supports efficient light distribution and reliable performance. With a rated life of up to 15,000 hours, this Metalarc Series HID replacement bulb offers long-lasting durability and reduced maintenance. Designed specifically for base-up (BU) operation, it should only be used in approved base-up fixture installations.