... silicone, heat-resistant to 200, sterilizable. Nipple: cross cut silicone nipple, heat-resistant to 200, sterilizable.Twist Cap: polypropylene, heat-resistant to 120, sterilizable.Bottle Cap: polypropylene, heat-resistant ... . Bottle sleeve: match with twist cap, polypropylene, heat-resistant to 120Features: 1: Safe silicone material, colorless, odorless, nontoxic, high and low temperature ...