Saavedra rims had aluminum alloy nipple washer that seemed to be specific to this Argentina made rim. They were a total pain in the arse to use, in that every nipple had to be inserted into said washer, then threaded into the spoke. If you got the spoke length wrong, it was a long and tedious process to take it apart and start all over again.
But man, they were light.
Wes Oishi
Los Angeles