As proposed, the main shaft of the tower was to be clad in stone, while the wings were to be made of glass.[1] The facade is made of Sardinian "luna pearl" that is cut into 13⁄16-inch (21 mm) slabs, measuring about 15 pounds per square foot (73 kg/m2). Each slab is attached to the aluminum curtain wall frame on all sides, supported only by the curtain wall. The stone panels are entirely prefabricated and are insulated with fiberglass panels measuring 2+5⁄8 inches (67 mm) thick, along with neoprene gaskets and silicone caulk.[2] The setbacks at the 46th and 62nd floors were designed with parapets of steel and concrete, which were reduced in size as part of a 1988 lawsuit settlement concerning the building's height.[17] Eichner disliked the parapets; he suggested that residents on the 46th floor "can look out at it and know they're looking at a wall instead of Central Park so that Helmut Jahn can rest easy knowing that his 'artistic integrity' is intact."[18][19]