Tunnel bags
If you go to the Arctic web page and click on the accessories tab, that will bring up the online catalog. Down in the lower right of the page go to page 8/9 or 26/27 and that is all of the tunnel bags cat has to offer. I think the one you are asking about is pn# 5639-618 or 5639-433.
Hope this helps!:face-icon-small-coo