Herman Miller Mirra Chair: Fully Featured - Adjustable Arms - FlexFront Seat - Tilt Limiter - Lumbar Support - Standard Carpet Casters - Graphite Frame/Citron Seat Firm, flexible Polymer back yields to the user's body shape to provide continuous support to the entire spine Mirra's FlexFront mesh seating surface evenly distributes weight and dissipates heat The built-in Harmonic Tilt mechanism creates balanced pivot points at the hip, knee, and ankle 12-year Herman Miller warranty with Born-On-Date sticker GREENGUARD certified, 96% recyclable , 42% of the chair material was derived from recycled resources