... .6m 17)Wallboard:EPS polyphenyl Colorful Steel Skin Boards75mm Thick, Tongue & Groove Style Compound Construction, Aluminum-alloy Frame,Anti-flame and ... ,Useful Life Time:25years polyurethane Colorful Steel Skin Boards50mm Thick, Tongue & Groove Style Compound Construction, Aluminum-alloy Frame,Anti-flame and ...