Filters aren't rocket science. By the time you've trekked through a few online retailers, pipe shops, pipe shows, and catalogs, you get the idea. But for a new pipe buyer just walking into the market, it's a lot to sort out, it seems to me. I have mostly tuned my relationship to filters so I can adjust and adapt, but it took me time and a bit of research. When newbies ask about pipe selection, they often don't ask about filters, and it's the first thing I think they might not know, that they need to know. It's inside the stem. I've never had a sales person attempt to explain it to me, or mention it at all, unless I ask.