"Plia" clear acrylic folding chairs by Giancarlo Piretti for Castelli

Set of 4 "Plia" clear acrylic folding chairs.  Designed by Giancarlo Piretti for Castelli Italy in 1970's.  In original very good condition. $1400 for 4.  Pictured with the Castelli Plana folding table (available in a separate listing).