These Polli monolithic outdoor furniture pieces were designed by Karim Rashid and Zachary A. Design, a Chicago-based manufacturer of sculptural furniture.

The Polli line appears to be made out of stone, but they're actually a proprietary blend of resin, stone aggregate and fiberglass; company founder Zachary Bitner, a furniture designer and SCAD grad, began experimenting with the mixture in the 2000s. The resultant pieces are all-season weatherproof and, unlike stone or concrete, lightweight enough that the pieces are easy to move.

The apostrophe-shaped backless version weighs 27 pounds, and the backed version isn't much more at 35 pounds.

Each seat is available in both left- and right-oriented versions.

They're made-to-order in Chicago, and available in a variety of colors.