Virco’s Analogy Series of school chairs includes 4-leg chairs with an ergonomically contoured polypropylene shell that flexes to accommodate different body types. The Analogy Chairs are available in 12”, 14”, 16” and 18” seat heights; there’s also an Analogy chair with an extra-large shell and an 18-1/2” seat height. The seat shells feature a waterfall front edge to promote good circulation in the user’s popliteal arches, lower legs and feet. The chairs also provide an excellent mid-back support and comfort to users of many sizes. The seat has contoured wrap-around flexible ribs, which are dynamically tuned to allow the upper back to flex more easily than the lower sections, a key to combining comfort and support.