One of the most popular mates used in Argentina and Paraguay. It is wood on the inside and aluminum on the outside. Starts by infusing a natural wood flavor into the yerba and will eventually season itself with a soft yerba flavor. Special instructions: This mate is natural wood and it not guaranteed against cracking or discoloration. Scrape out the yerba and let dry immediately after each use. Do not cure. Do not leave the mate wet. The wood on the inside will expand too fast and crack the wood on the outside.