When using the MESA V2 with a smaller child to achieve proper harness tightness and chest clip placement.
Remove the optional harness pads before securing the child. The manual also states they must be removed when securing a preemie.
As the child grows, keep these fit criteria met: harness straps are at or slightly below shoulders, and the bottom of the headrest is positioned at or up to 1 inch above shoulders.
Pull the head restraint adjuster tab and slide the head restraint up or down until the harness rests at the shoulders or slightly below and the headrest is positioned correctly.
Remove only after all fit criteria are achieved: harness straps are at or slightly below shoulders; bottom of the headrest is at or up to 1 inch above shoulders; chest clip is at armpit level; crotch buckle rests securely against the child with no gaps and the child is not sitting on top of the buckle; there is room to tighten the harness properly; and the child is not slouching. UPPAbaby notes the insert is designed/recommended for 4–11 lbs and may remain beyond 11 lbs until all criteria are met.
Once all listed fit criteria are met without it, remove the infant insert.
If the child is on top of the buckle in the inner position.
Unbuckle the harness, flip the carrier over, insert the metal clip completely through the shell and seat pad, move the buckle to the outer slot, then check that it is securely attached by pulling up on the buckle.
By first birthday or when the child meets the 35 lb weight limit, exceeds 32 in in height, or the top of the head is less than 1 inch from the top of the headrest structure in its highest position — whichever comes first.
Stop using the MESA V2 and move the child to a convertible car seat. In the next seat, keep the child rear-facing as long as possible.