Wider base to accomodate A+ chairs. Built for today's larger students. MODEL SHAPE HEIGHT DESK 9906 Study Desk 26''-34'' Adj 20''x26'' 99B6 Wire Bookbox 26''-34'' Adj 20''x26''OPTIONSPermaTuff EdgePlywood Core Work SurfaceSolid Plastic Work SurfaceNon-Skid GlidesQ-Ball GlidesBlack Edge30'' Fixed Height