Made of a breathable mesh exterior and a wicking knit interior, the Ergobaby Performance Infant Insert cushion must be inserted to support growing babies ranging from newborns to 4-5 months. The proprietary design keeps pressure off a baby's developing sacrum. The Performance Infant Insert also provides the necessary head and neck support for comfortable carrying from Day 1. The Performance Infant Insert snaps around the baby, can be adjusted as needed and placed with ease inside any Ergobaby Carrier. Cozy and protected, your baby will be perfectly cradled and cushioned.