Chicago Metallic® 260 Aluminum Cap 15/16" Exposed, Fire Rated acoustical suspension system is available in intermediate and heavy-duty designs, and is built with HDG 30 steel with an 100% aluminum cap for added corrosion resistance in interior environments. Featuring demountable hook-end cross tees for a quick and easily assembly, this Chicago Metallic™ grid systems is third party certified to meet ASTM standards.