How to install a Dometic AC542 Faucet
First, place the large foam o-ring over the faucet hole cut-out.
Next, place the same sized metal o-ring over the gasket with the grooves facing up.
Place the assembled faucet on the grooves from the metal o-ring. While holding the faucet in place, tilt the sink to the side.
Take the rubber "U" washer and metal washer and the threaded rod and attach them to the bottom of the faucet. Install the hoses before tightening the "U" washer completely.
This image shows how it should look so far once everything is tightened down.
At Panther RV Products, we leave these two o-rings out of the install, they end up making it more complicated since they never fit properly.
Also you may have a little bit of an overhang, depending on the sink. This is common.
And this is what your final product should look like.