The Avent Pack Natural Response Ultra Air Bottle Scd837/11 is a bottle designed to make feeding your baby easier. To use it, first make sure it is clean and sterilised. Then, place the teat on the bottle and secure it properly. Fill the bottle with your baby's milk or formula and secure the lid. Make sure the nipple is full of milk before feeding and hold the bottle at an angle to prevent the baby from swallowing air.