DESIGN & DETAILS: Premium nylon-spandex exterior with a DWR coating sheds water without adding bulk 0.5 mm neoprene core for lightweight insulation Soft, smooth and hydrophobic interior feels great against bare skin Titanium-laminate adhesive helps retain body heat. Anatomically shaped left and right feet for a superior fit and unmatched comfort. Pairing snaps prevent you from hitting the river with only one sock.