TwinGo Panel Extender allows the TwinGo Carrier to grow with your child! This accessory extends the height of the carrier to provide additional head and neck support for small babies and additional back support for large toddlers. The Panel Extender can be used during two developmental phases: newborn and toddler stage. For newborns, only use Panel Extender in combination with TwinGo Infant Insert staring at 7 lbs until your baby has strong and consistent head and neck control.