Apparently you can purchase them online.
These breads are more wheaten and have three different incised designs which have a significance for one receiving in the hand. 500 wafers (two packets of 250) in decorative box. Cavanagh Company offers by far the best altar bread. All breads have a carefully molded sealed edge which prevents crumbs. They are baked of only pure wheat flour and water and are made strictly without additives. Cavanagh breads are produced in the United States in an exceptionally clean and modern automated facility. The breads are sealed minutes after baking and are untouched by human hands. Cavanagh packaging is superior to all other forms and many options are available to meet your individual requirements.
I was referring to these:
Did you see my pictures from Rome?