Libera is a chair with polypropylene shell, STACKABLE 4 legs fixed base, polypropylene jointed glides.AVAILABLE MODELSLI | Polypropylene shell.LC | Polypropylene shell with padded seat.COLORS & FINISHINIGAvailable in different colors and finishingsCERTIFICATIONSEN 16139 / EN 1022 / EN 1728