... Liquid silicone rubber with nylon material inside,soft feeling, durable and tensile of its physical characteristic,100% silicone,heat-resisting, ... )It can used in the refrigerator,freezer,microwave,and oven.5)Heat resistant up to 230F and down to -40F6)Flexible ... to fit for the babies mouth when baby sucking Outstanding resistance to aging. Right silicone ,Right choice! The baby like silicone spoons