Nylon composite base creates a look that is less clinical. The polyfoam cushion has a core of high-density foam with a extra soft and comfortable layer of foam on top. Height range: 191/2– 25.When ordering, specify tile or carpet casters and base color: Black, Slate or Putty. Choose from Vinyl Color Options : Windsor Wine, Cambridge Blue, Black, Emerald, Ninja, Smoke, Fawn, Mountain Violet, and Earthen Brown.