STYLE CARTEL MOM - New All-in-One, Group 1-2-3 Child Car Seat from Britax Römer We were recently introduced to the new car seat on the market. Britax Römer has unveiled its new five-point-harness child car seat that transforms into a highback booster seat as the child grows. The new seat, EVOLVA 1-2-3 SL SICT, provides superior safety for children aged 9 months through to 12 years (9kg-36kg) and is available in five colours.