This Knot chair is by French industrial design consultancy Studio Désormeaux/Carrette (a/k/a designers Nathanaël Désormeaux and Damien Carrette).

"The skeleton of the chair is made up of two curved aluminum tubes that support each other. Nested one inside the other, the hangers become a self-supporting structure offering the chair its main function: seating."

"The knot, usually synonymous with complexity, has been reworked and redesigned here to create a visual paradox: it brings stylistic and functional simplicity. Treated in curves, the two curved tubes of the chair, nested one inside the other, suggest embracing and invite the user to take part in this movement. The volume formed by these two pieces evokes a handmade drawing which contributes to the familiarity between the object and its user."

"Knot innovates by integrating its production cycle. Double-direction bending machines allow the production of both short-radius hangers and variable-radius hangers, thus avoiding the rework of parts and therefore the production of tools."

The chair appears to have been done as a concept for seating manufacturer Via, but as far as I can tell it's not in production.