This pair of iconic wrought iron frame BKF-Butterfly lounge chairs by Jorge Ferrari-Hardoy for Knoll is simple yet elegant design. The Butterfly chair model consists of an open, criss-crossing, tubular wrought iron frame with a leather sling seat that slips over the frame. The newly produced, thick tan leather covers on these chairs feature hand-sewn, saddle stitching with one horizontal seam that places the sitter in a comfortable upright position.

The butterfly chair was designed by Argentine architects Juan Kurchan, Antonio Bonet, and Jorge Ferrari-Hardoy (but Ferrari-Hardoy is considered to be the primary designer), who were inspired by the British military folding chair known as "La Tripolina." The chair became popular in the United States during the mid-20th century and has since become an iconic piece of modern furniture. Its simple yet stylish design and comfortable seating have made it an enduring design choice.