Tesla MODEL X 2015 Owner's Manual page 49

If the child restraint system moves away from the seat,
both latches are not fully engaged onto the seat's
anchor bars. You must reinstall it and try again. It is
critical that both latches on the child restraint system
are fully engaged.
WARNING: Do not use ISOFIX/i-Size anchors with
child restraint system or booster seats that have an
integral safety belt where the combined weight of
the child plus the child restraint system exceeds 33
kg.
Safety Leg
First and second row passenger seats in Model X
support the use of a child restraint system with a safety
leg. If the child restraint system is equipped with a leg,
extend the leg as described in the instructions provided
by the manufacturer of the child restraint system.
Attaching Upper Tether Straps
Second and third row seats support the use of upper
tether straps. When the instructions provided by the
manufacturer of the child restraint system include
attaching an upper tether strap, attach its hook to the
anchor point located behind the associated seat.
NOTE: Tighten upper tether straps according to the
instructions provided by the manufacturer of the child
restraint system.
The anchor points for tether straps are located on the
back of the second and third row seats.
For dual-strap tethers, position a strap on each side of
the head restraint.
WARNING: When routing tether straps, keep the
strap close to the headrest as illustrated below. On
a Model X equipped with third row seats, do not
allow a tether strap to cover the third row access
button on the rear shoulder of the seat.
Seating and Safety Restraints
Child Safety Seats
WARNING: USE ONLY SEAT BELT RETAINED
CHILD SAFETY SEATS IN THE CENTER SEATING
POSITION.
Dual Straps - Second Row Monopost Seats:
Dual Straps - Second Row Bench Seats:
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