For those in Mexico this may be useless, but for the rest of us, you
can call Southdown, at 800-526-1753 and press 0 and ask for dealers
in your area. They seem to restrict themselves to the NE part of the
US, so that is a problem for some. You may be able to get your local
home depot / lowes to order it for you from Southdown / Yardright. I
belive the SKU for Home Depot is 578-819.
It took me a while to get that phone number - they don't post it on
the Yardright web site.