If you're a CW operator this greatly enhances your operating ability!
Adding this crystal filter to your radio lowers the IF passband down to 500 Hz, enough to help you pick out those CW signals that are very close together but still wide enough that you can tune up and down the band looking for those much needed contacts easily.
It was very easy to install and after making the one menu change worked immediately. I would highly recommend it for any one seriously into CW operation.