When should I adjust the Infant-thingy head support?

The position of the head support should be adjusted whenever you adjust the height of the harness straps for your child or if the top of your child's head goes above the top of the head support.

• The attachment tabs should be positioned in the third harness slots above the slots your child is using. 
• If needed, the head support attachment tabs may be inserted through the fourth set of harness slots above the harness slots your child is using in order to prevent the top of their head from going above the head support.
• Discontinue use of the head support and install the car seat headrest when your child's head is at or above the top of the head support in its highest adjustment position.

The Infant-thingy's head support can be used until the top of your child's head is above the top of the head support when the head support is in its highest position, at which point it must be removed and your car seat's headrest installed instead.