Your baby’s age, duration of feeding time and drinking amount will be your guide for choosing the best nipple hole size. Babies of the same age will have different requirements. So select the best size according to the development of your baby. When your baby is taking longer times to finish drinking, even if ventilation is working well or the nipple keeps collapsing, please upgrade to the next size. Guide for size of nipple hole of SofTouch™ Peristaltic PLUS Wide-Neck Nipple
| Size | Age in Months | Type of Nipple Hole | Feeding Time and Amount |
| SS | Babies 0+ Months | Round Hole | About 10 min for 50ml |
| S | 1 Month Old Baby Onwards | Round Hole | About 10 min for 100ml |
| M | 3 Months Old Baby Onwards | Y Cross-Cut Hole | About 10 min for 150ml |
| L | 6 Months Old Baby Onwards | Y Cross-Cut Hole | About 10 min for 200ml |
| LL | 9 Months Old Baby Onwards | Y Cross-Cut Hole | About 5 min for 200ml |
Also, if your baby grows comfortable with one certain nipple, he or she may object if you change to a new one. Rotate the use of 2 or more nipples for about 2 months before replacing them.