What height will this suit in full harness.

Hi Jo, Thank you for your enquiry.  The Boulevard 70 can be used until your child is approximately 29.5kgs maximum weight or 124.5 cm tall although this depends on if your child carrys their height in their legs or torso.  We recommend you take your vehicle and child into your nearest Baby On The Move store to try out different seats to get the best fit for both your child and your vehicle. We hope this helps with your query.