You fellas can make fun of the "air tight" wording, but that is how it is worded at practically all commercial campgrounds.
If your RV site does not have a sewer connection or you are only going to be camped for a few days, don't bother to connect your sewer hose. But lets suppose you are going to be camped for two weeks and will be needing the sewer.
Then, since this is your first time out, you need to "make up" your sewer hose by installing the clear-plastic 45 degree sewer connector on one end of your new heavy duty sewer hose and the combination 3-4" threaded connector on the other end. Be sure that the sewer hose is pushed onto the fitting as far as it will go, and then tighten the large hose clamps securely—you really don't want these fittings or the hose to leak, even a tiny bit!
Now, screw in the threaded connector to the sewer fitting at the RV site. If the site sewer fitting is just an open pipe with a rock over the top, you will need to use the rubber donut between the sewer pipe and your sewer hose to have an air tight seal.
Now, remove the travel cap that covers the RV sewer drain connection on your motorhome, and twist on the clear elbow fitting to your RV's sewer connection
Utility Hook Ups