Britax Kid Guard Booster GreyThe latest addition to our 4 10 year Booster Range! The Kid Guard provides continued safety from first booster use until your child is approx. 135cm in total height 4 years to 10 years of age (approx.) or when shoulders meet the maximum height markers. With its expandable lower side wings, extendable seat base, Active Head Restraint (AHR) and 9 position adjustable headrest, the Kid Guard grows with your child delivering comfort and safety on the move.