Hey, I'm not a pro, but from what I hear, there are basically two types of connections. Slip-on's that have a o-ring for the water connection, and a set screw to hold it in place, or those that screw on with a pipe fitting. If your new one has a setscrew to hold it in place, it should have an o-ring there to seal it as well. Now, there's probably other versions or ways to do things. Check if there are threads on the recesses of your spout if there isn't a setscrew to hold it. If it has internal threads, then you'll need to add the male fitting to the stub coming out of the wall. Getting it the right length so that it tightens up where you want it with no gap at the wall takes some skill. Did the spout come with installation instructions? or what does it say on the packaging? That should give yo uan idea of how it should be attached.