[Adrian E]

Hiya

Speaking from experience, spend a decent amount as this is the child restraint they'll be in for by far the longest!

I highly recommend the BeSafe iZi Up Fix X3:

https://www.besafe.com/product-category/child-car-seat/

The Isofix is only used to restrain the seat in the car and stop it moving about either when in use or not - it gives the added advantage of extra side impact protection as the seat is designed to swivel on the base, to move it away from the point of impact. Unrestrained high back boosters are a royal pain in the arse!

The quality of high back boosters is highly variable - as a manufacturing engineer by training, and a research engineer into child safety amongst other related areas, this product is by far and away the best one out there in its class.

This place is local-ish to you and sells it for £170 (you can get 5% off if you complete an order within 5mins/using BABYCO5 code) but you may find it cheaper elsewhere if you shop about - just make sure it says 'fix' in the model description or you're getting the inferior non-Isofix variant.

Your offspring needs to be fairly well up the weight/height range before moving to this stage of seat - ours moved up as he was literally at the weight limit for the harness seat, so it was no longer safe, but was well under 3 yrs. The seatbelt was a little high on his neck until his next growth spurt. He's now getting on for 8 and still using it daily!

Hope that helps

Adrian

ETA - other thing I forgot to describe is the adjustment mechanism, which is genius! It's like a worm and peg as the top and bottom halves extend relative to each other (most just move the top bit up and the bottom stays static) - at the same time the side wings expand as it goes up (again most don't adjust).