With ergonomics in mind, Hierarchy is a colorful and flexible solution for stimulating focus and motivation in your learning environment. Multiple sizes, bases, and vibrant colors for all ages of learners. Flexible and ergonomically shaped seat with lumbar support for easy position changes, eliminating stagnant environments. Smooth reinforced back allows for flex action without sharp ridges. Upholstered seat version available (16″ and 18″ only) with your choice of graded-in fabrics.