Easy-to-clean One Piece Lid with no small parts to lose;Interchangeable lids fit most of The First Years reusable cups;Sweat-proof surface and double-wall insulation to keep liquids colder for longer;Dishwasher safe;BPA Free, Phthalate Free;Sweat-proof surface and double-wall insulation to keep liquids colder for longer;BPA Free; Phthalate Free