Forgot to mention, that Gaiwan (set) is able to fill up 4 cups. About 100ml capacity. So that set can be used from 1 to 4 person presentation.
Edit: I thought I am buying a porcelain, but from the label it says ceramic
Which I guess why it has some effect on water...
Unrelated product, but is made from ceramic. See the description for using ceramichttp://cgi.ebay.com/LOHAS-Natural-Ceram ... ltDomain_0
LOHAS Natural Ceramic Ball has a high surface area, and adsorbs many compounds. Water brewed with ball could be get rid of organic contamination, taste, or objectionable odors. Put the ceramic ball in a kettle can remove chlorine from treated water, removing any residual protection remaining in the water protecting against pathogens. Put the ball in your teacup can remove astringency and make your tea tastes mellow. You may also use it in wine, beer, soup or cook it along with rice.