12" wide hip width with 5" of vertical adjustment. Seat can be adjusted vertically to raise rib and shoulder supports. Head can be adjusted vertically and horizontally, can also be rotated to increase peripheral vision. Unique shoulder support cover design allows extra 1" shoulder width adjustment. Vertical and lateral adjustable head restraint uses molded high density energy absorbing impact pad to eliminate upholstery on head restraint. Kit comes with black cloth cover. Seat cover insert kit is available to reduce width for smaller kids.