I found my Clarion VRX8370R in the Camper I bought and I wasn't able for month to understand it.
The Owner Manual was perfect and just what I was searching for.
Text excerpt from page 13 (click to view)
Insert the ducting spigot into the aperture on the top of the cooker hood casing.
Fitting the Wall Cabinet
If it is necessary to fix the kitchen cabinet to a hollow construction plaster or partition board structure then it must be sufficiently reinforced to be strong enough to support the weight of the cooker hood.
Wall Cabinet Preparation
Position the cooker hood upside down, ensuring the cooker hood is supported. Open the visor and remove the two metal grease filter cassettes (see maintenance and cleaning section). Mark the position for the cut-out for the cooker hood on the underside of the kitchen cabinet. The cut-out should measure, lenght 503 mm by depth 162 mm. Mark the position for the cut-out for the ducting on the top of the kitchen cabinet ensuring that the centre of the hole aligns with the centre of the ducting spigot. A pad saw or similar cutter will be required to cut the rectangular hole for the cooker hood and the circular hole for the ducting spigot. Before inserting the cooker hood inside the cabinet ensure a hole has been provided to route the mains cable.
KSecuring the cooker hood to the wall
1. Insert the upper casing of the cooker hood through the hole from the underside of the cabinet ensuring that the butterfly bracket screws have been loosened sufficiently to allow the wings to be folded back. Tighten the butterfly bracket screws, by rotating the screws clockwise. If further alignment of the cooker hood is required the lower section of the casing can be adjusted horizontally, backwards and forwards.