Chair and work surface in an ''all in one'' convenient package. MODEL SHAPE HEIGHT DESK 7458 A+ 18.5'' 18''x24'' 7457 A 17.5'' 18''x24'' 7455 B 15.5'' 18''x24'' 7453 C 13.5'' 18''x24'' 7458 - NBRK A+ 18.5'' 18''x24'' 7457 - NBRK A 17.5'' 18''x24'' 7455 - NBRK B 15.5'' 18''x24'' 7453 - NBRK C 13.5'' 18''x24''OPTIONSPermaTuff EdgePlywood Core Work SurfaceSolid Plastic Work SurfaceSeat and Back PadsBlack EdgeNon-Skid GlidesQ-Ball GlidesSteel Glides