... and base used alone9-18kg(about 9 month----4years old child),taking the 5-point harness system to protect your ... install the baby car seat15-36kg(about 3-12years old child),taking the 5-point harness ,fixed kids and seat ... with 3 point belt22-36kg(about 6-12years old child),convert to a non-back cushion easily,fixed booster ... design,colors and fabricEasily installed by 3-point belt child safty seat