Yep they do. Some stores still have old stock, not so much old but there was a first release of the Meridians that came out with covers that have lower markers than the second lot. So if you have a Meridian or purchase one that you feel the markers are low on, find the DOM (date of manufacture) on the seat and call Britax Australia. They will know from the DOM which seat & cover you have and if it is the old cover with low markers they will arrange to send you a new cover with the correct higher markers So if you have a 6 month old that looks like they are at the markers to turn forward-facing, you may have an old cover (or a huge/tall 6 month old ) But it's worth enquiring you will get quite a bit more rear-facing time with the new cover. The lines for move to booster would be too low as well so even if you have an older forward-facing child you want them harnessed for as long as possible so would benefit from the new cover too.