Main cabin rear floor hot air vents.
The vents are fitted in three places, the vent inlet fits over the floor outlet flange and is bolted to the floor using the two bolt holes indicated by the arrows.
Here, the vent inlet can be seen with the cable operated flap valve that fits inside the floor outlet. Push the vent inlet over the floor outlet until the locking tang lines up with the indent in the outlet.
Once the vent is fully home, it will be seen that the bolt holes in the vent bottom plate will line up with the bolt holes in the floor, fit the bolts.
Also, here can be seen the operating lever and cable.
Here the vent is fully fitted.
Here, marked by the arrow is the tang that must be bent down into the indent in the floor outlet.
Finished job.....now do the other one.