i believe the kit they're talking about is the one described in the instructions at bseries.net.

you can get the kit already made for $16 shipped, i believe. i don't remember the email address to contact, but if you do a search, you'll find it.

i didn't like the fit of their cut pvc pipe though. it felt extremely awkward when i was trying to position the antenna on the fender, so i ended up not using it. what i used instead was the metal piece that sits on the stock antenna assembly just under the fender. it mates perfectly with the plastic base that sits on top of the fender (of course), so it made the fit of the s2k antenna perfect (with some changes to their kit as well, of course).