Jobri’s most popular designed kneeling chair featuring a strong, rugged frame with easy height adjustment. PLUS edition has added benefit of Visco Elastic memory foam. Black steel frame with nylon casters.Gas height adjustment.Visco Elastic memory foam covered with durable fabric.Overall width:27" (Star Base).Height range:22" to 27"Seat size:16.5" x 14.5"Knee cushion size:16.5" x 9.5" non-molded foam.Optional Back available.