BestOffice Home Office Chair Ergonomic Desk Chair Mid-Back Mesh Computer Chair Lumbar Support Comfortable Executive Adjustable Rolling Swivel Task Chair with Armrests,BlackEasy To Assemble We provide all the tools and the detailed instructions for you. No additional tools needed for assembly. For your convenience, all screws have extra backups. It is easy to assemble this office chair by yourself at home. Ergonomic Design Designed with human oriented ergonomic construction. streamlined armrests fit the curve of your arms,allowing you to sit comfortably on a work chair. The locking mechanism is easy to adjust the height,