The ingenuity of the Parentesi lamp, first released by the Italian lighting brand Flos in 1971, is most evident when it’s handled: Slide the nickel-plated tube along the steel cable to a desired position, and because of friction created by the materials, the apparatus magically stays in place. The function is the result of an unusual collaboration between two Italian giants of design, the architect and designer Achille Castiglioni and the designer Pio Manzù, the latter of whom produced several streamlined, now-iconic creations, including the Fiat 127 and Alessi’s Cronotime desk clock, before his death in 1969.