The new quartz car safety seat is the latest addition to the complete crs range from jan quartz is a restraint system that uses isofix fasteners designed for group 23 from 15 to 36 kilograms approximately 3 to 12 years technologically advanced quartz is fitted with proportional height adjustment an integral adjustment system that lets you regulate the height by up to 11 positions when the height of the seat is extended it is not just the headrest that moves the backrest also moves to t