Gutter guards. I'm not a fan, however they do serve a purpose.
One thing to remember, try to make sure that you can remove them sometimes to clean them out underneath. After a while the plastic gets harder and they seem to snap to easily when lifting off the gutter.
How you can do this? Trial and error. depends on what type they are.
During heavy rain, get ready for a wet area around the house that does not always show up. If you already have water issues, monitor them during a heavy rain. We have had folks have to remove them later on.
Just giving you a little heads up.