PU Leather Hydraulic Lift Adjustable Height Swivel Office Desk Chair Black (1012-5) Swivel Seat -so you can turn around while sitting, Tilt Tensions -so you can lean back, Hydraulic Lift -so you can go up and down, Rolling Chrome Base -so that you can move easily around the room. Seat Height :15" - 22", Back Seat Height: , Seat Width :20.5", Seat Depth: 18.5". Weight Limit 250 Pounds 6' Tall UPDATED VERSION: customers have told us in the past that the regular wheels do not work well on hard (wood) floors and so we upgraded the wheels to higher quality rubber/plastic so that they will work smoothly on hard (wood) and soft (carpet) floors. We have also added memory foam so it is more comfortable, We have also widened the base so it sits more confidently,