Most of the convertible seats that only go up to 9kg are made by IGC. Personally I don't like them. They are cheaper for a reason. Many of the rear facing arms that fold under for forward facing tend to warp out of shape long before a child reaches 18kg forward facing. I am very picky now that I have tried them, and I will not buy a rearfacing seat that does not go up to 12 kg.