Duorest Smart, Ergonomic Home Office Task Desk Chair - Water Resistant Knit Fabric Fully adjustable dual backrests to fit perfectly for all body size Pneumatic seat height adjustable for individual fit Height, Width, Pivot Angle adjustable Armrest - Aluminum Die Cast for better durability Luxurious Aluminum Die Cast Triple Y Wide Base for better stability when reclined Meets or exceeds all U.S. home office furniture industry standards (ANSI/BIFMA)