Lifetime stacking chairs are made of high-impact polyethylene, contoured for comfort and designed for durability. powder-coated tubing increases strength and stability. also, the powder-coated tubing increases strength and stability. lifetime stack chairs are lightweight, easy to clean and can be used indoor or out. the convenient design allows you to stack multiple chairs together for easy storage. the chairs exceeds demanding bifma standards and are perfect for your next meeting, event or family gathering. purchase in this package of 4 for instant savings.