Savaria Toyota Sienna Owner's Manual page 14

4. Allow the retractor to spool in and remove excess slack in the tie
down once the J-hook has been attached. Two front retractors are
required per wheelchair.
5. Attach the Q'Straint rear Slide 'n Click retractors by sliding the
anchor of the retractor over the appropriate disk on the floor until
it clicks in place. Rotate the assembly until it faces the front of the
vehicle.
To remove the rear retractor, lift the lock plunger at the back of the
retractor and slide the assembly rearward off of the disk in the floor
as shown below.
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