I need a Woofer For A Proac 2 not a 2's

I have been looking all over for a Woofer for a Proac 2 ....It is not the same as a 2's.....Any help ???
I believe it is the Scanspeak 18W/8543 Polypropelene woofer. BTW, the 2 and the 2S use the same woofer.

Check out http://www.madisound.com/scanspeak.html