SmartLink Four-Leg Chair, 19.5" x 19.63" x 31", Onyx Seat, Onyx Base, 4/CartonSmartLink chairs feature responsive contoured geometry to support the way people move, allowing them to turn around, sit sideways, lean back, and stay comfortable and focused for longer periods of time. This four leg armless chair supports learning by allowing for a variety of postures. The single piece seat is easy to clean and maintain. Tubular steel frame withstands anything students throw at it. Stacks up to five high on the floor to clear room