The Soft Bottle nipples are extremely soft and gentle for your baby to suckle and are available in different flow rates to suit babies from 0-18 months. Due to the unique valve, the nipples prevent the hard suckling needed with conventional bottles. The Different Types of Soft Bottle Nipples Level 1 - Slow Flow wide neck BornFree Nipple is recommended for babies 0-3 months. Level 2 - Medium Flow wide neck BornFree Nipples, recommended for babies of 3-6 months. Level 3 - Fast Flow wide neck BornFree Nipples, recommended for babies of 6 months plus. It also operates as a Medium Flow nipple with some thicker types of formula. Y cut - Wide neck BornFree