Why is Medela Calma available in only 1 size?

Multiple nipple sizes are not required as the baby controls the flow of milk through vacuum.  The baby will apply more or less vacuum to Calma as its need for milk changes throughout breastfeeding duration.

This Question Applies to:

Calma® Breastmilk Feeding Set with 5 oz Bottle

Calma®

Calma® - Breastmilk Feeding Nipple