Like all other MAXNOMIC® size categories the OFFICE SERIES is built to last! Its metal steel frame is enclosed by our custom-molded cold cured foam for maximum sitting comfort. We use durable PU leather for the chair cover. An ergonomically shaped backrest will demand a healthy posture without compromising comfort. All chairs come with heavy-duty parts which include an aluminum chair base, a class-4 cylinder, a heavy-duty tilt mechanism, and sturdy 4D adjustable armrests.