HPFi | Tone seating features lightweight and durable polypropylene seats engineered for optimum comfort. Backs are available in cool, breathable mesh or solid, lightly textured polypropylene surface. The two-piece clamshell construction of the seat ensures comfort whether it is solid or fully upholstered. Armless and armchair versions are perfect side/guest chair companions for the ETC swivel desk chair, breakrooms, training rooms, lobbies, etc.