Britax Roundabout 55 Guide D'utilisation page 21

To adjust the buckle:
Unbuckle the harness.
1
Remove the belly pad and
push the buckle through the
cover.
Turn the buckle webbing
2
and slide it between buckle
positions.
Slide the buckle retainer into
3
the buckle slot, and ensure the
red release button faces out.
Child Seat Functions
19