Britax safe-n-sound BS0072E-i20133 Instructions For Installation & Use page 23

Next type of restraint that can be used in the car for your child.
When your child has outgrown this seat, you can use:
• Or a harnessed car seat with in-built harness suitable for
children approximately 6 months to 8 years old.
• A convertible booster seat with in-built harness until
approximately 4 years old and then as a booster seat with
vehicle lap-sash seatbelt or seatbelt and compatible child
harness until approx 6 to 8 years of age.
• Or a dedicated booster seat with vehicle lap-sash seatbelt
or seatbelt and compatible child harness until 6 to 8 years of
age or until 8 to 10 years of age.
Instructions for Installation & Use
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