This Black Modern Mid-Back Ergonomic Mesh Office Desk Chair with Armrest on Wheels comes with all hardware & necessary tools. Follow the desk chair instruction, you'll find it easy to assemble, and the computer chair estimated assembly time in about 10-15 mins. Desk chair using high-density sponge cushion, more flexible, office chair with a middle back design, rectangular ornament not only as a decoration, it can provide good lumbar support makes you feel comfortable. All the accessories of our office chair have passed the test of BIFMA, which is a guarantee for your personal safety. The mesh chair can bear the weight of 250 lbs. It is a good choice to add one of our computer chair in your office or put a desk chair in your home/activity room. The seat height can be adjusted from 17.1"-20.3" and the seat measures 18.5"(W)*18"(D). The cushion of office chair, armrest accord with human body engineering design, let your body and mesh chair perfect fit, suit long time use, give you creative design! Office chair desk chair adjustable chair ergonomic task chair rolling chair swivel chair mesh chair computer chair armrest chair desk chair adjustable chair ergonomic rolling swivel task chair mesh office chair armrest chair rolling chair swivel chair mesh chair executive chair task chair office mesh chair computer desk chair mesh chair armrest chair suitable adjustable chair mesh chair office chair ergonomic task chair mesh chair computer chair mesh chair executive chair rolling chair swivel chair mesh chair rolling chair swivel chair.