Balt hierarchy 12″ plastic classroom chair – set of 5 – orange 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. features: 4-leg base available in four seat heights: 12″, 14″, 16″, and 18″ with heavy gauge chrome coated steel base. include nylon swivel glides.