BB Boom IZZA Notice D'utilisation page 31

2. Press and push ISOFIX release button on both sides of the seat and make the
ISOFIX connectors are fully extended. This ensures that both hooks on the
ISOFIX connectors are open and ready to use, now both ISOFIX indicators of
ISOFIX release button show red color .
3. Push the ISOFIX connectors through ISOFIX guides directly into the
anchorages until heard an audible sound "click". Now both ISOFIX indicator of
ISOFIX release button show green color . At the same time, push the backrest of
the base of the enhanced child seat as soon as possible toward the backrest of
vehicle seat until tightly.
Make sure that both ISOFIX indicators of ISOFIX release button on both sides
show green color so that the enhanced child seat is correctly fastened.
click
RED
GREEN