I have a shower panel with a 5 port diverter (1 inlet and 4 outlets - one of which is plugged to act as the off position). The shower recently started leaking and I removed the ceramic catridge but I am unable to find a replacement. It is a 40mm unit with a 4 oring bottom and is the one show in this website

atrade.com.tw/ArticleShow.asp?ArticleID=395

Any help locating this cartridge would be most appreciated. I have been to all the stores in Denver!