Jane xtend impact shield technically known as an impact shield xtend is a protective cushion that effectively operates as a child retention system the easy to use accessory means that children of between 9 18kg group 1 can safely travel in seats that are designed for group 2 and 3 essentially by adding the xtend to either montecarlo model the car seat can be used for children from 9 36kg in weight approx 9 months to 12 years xtend compatible with the jane montecarlo montecarlo plus