... ,heat-resistant to 200 ,sterilizable. Twist Cap: polypropylene,heat-resistant to 120,sterilizable. Bottle Cap: polypropylene,heat-resistant to 120,sterilizable ... . Bottle sleeve: without handle ,match with twist cap,polypropylene,heat-resistant to 120. Features: (1),safe silicone ... your baby. (2): Please don't spin the twist cap too tight or too loose to prevent leakage of milk ...