This is not just another plastic Sippy Cup. This is the one of a kind, Superb Sippy Cup with a flexible, bendable, re-usable silicone straw! The inner body straw is made of robust Tritan™ to ensure it performs continuously and effectively day after day! The 20 Oz./600 Ml. capacity stays cold for up to 24 hours because it is copper lined & double wall vacuum insulated with 18/8 stainless steel. It is ideal for everyday use at home, school, or office.