Chicago Metallic® 4200 Integrity™ 9/16" Exposed drop ceiling grid system is built with HDG 30 steel and features a heavy-duty design. Every one of our grid systems is third party certified to meet ASTM standards and is listed with ICCES Evaluation Services, reference report ESR-2631 for more information. This acoustical ceiling grid features seismically approved stab-end cross tees with a narrow face that creates a premium double-reveal aesthetic.