Opalith-Plattchen (with an umlaut over the second 'a') are made by:
Chr. Graze KG
Fabrik fuer Bienenzuchtgerate (umlaut over last 'a')
7056 Weinstadt-Endersbach Bei Stuttgart
Germany
telephone 0 71 51 6 11 47
telex 7 262 213 apig d
fax 7151-609239
As of 13 September 1991 tags were DM 22.50 for a kit with 500 tags (100 each
of 5 colors), plus DM 5.00 for airmail shipping.
 
The tags are also available from retailers, including:
        Gustav Nenninger
        8741 Saal A. Saale
        Germany
 
        Bienen Mathys AG
        3762 Erlenbach i. S.
        Switzerland
 
This information is from the appendix on supplies for pollination
biologists, in a book called Techniques for Pollination Biologists, to be
published by University Press of Colorado later this year.  Carol A. Kearns
and David W. Inouye, authors.