12-HD980 Heavy Duty Steel Mullion Designed for double door applications from 8–10 feet, the HD980 Heavy Duty Steel Mullion is fire-rated and offers maximum strength and reliability when used with the 8800 Series Rim Exit Device. Downloads Catalogs Instruction Manuals Promotional Sheets Product Templates Parts Manual Interested in this product? Contact Us Related products 980S & 12-980 Removable Mullions L980 & L980A Keyed Removable Mullions 650A Removable Mullion