The Britax Safe-n-Sound Hi Liner SG is a height adjustable tethered booster seat with side impact protection wings. When fully extended, it is one of the tallest booster seats (at 855mm) and will fit the tallest of children – if not then they will very likely fit in your regular car seat anyway. Supporting this is a 5 star safety rating (on the old CREP standards) and valuable safety features: EPS wings for side impact protection in case of an accident, a top tether strap to ensure the booster remains tethered to the car, and an anti-submarining clip Britax calls SecureGuard to ensure the belt remains in the correct position.
The Hi Liner SG is a good quality seat, but at $219 has a price to match the premium features.
