The Holophane HL Series B 400W S51 Lamp LBF2-5024 Ballast Assembly MB4C400HP48 is a high-quality ballast transformer designed specifically for commercial and industrial lighting applications. With the trusted Holophane brand name, this ballast assembly ensures reliable performance and energy efficiency for your facility lighting needs. Perfect for maintaining and upgrading your existing lighting system, this product provides a durable and dependable solution for your business or industrial space.