Polypropylene shell reinforced with gas injection. Steel tube structure with Grey epoxy paint finish. Cut-out backrest allows “breathing” for greater comfort. Lumbar support reduces fatigue caused by long periods of time in a sitting position. Wide seat maximizes comfort and attention in the classroom. Anti-balance system, without edges, rounded profile for a correct knee flexion angle, helping blood circulation. Higher resistance to impacts, scratches and wear. Does not require maintenance. Design without recesses for simple and quick cleaning.