The number one been the waterman's smallest fountainpen in the world this is the one size biggest that few known to exist in working order. The waterman's in 1995 the price tag was $5,500 in selected pen shown and not readily available in any pen show and the peter pen was around $1,900.It is not something you use (you can if you want too) is solely for display, rare and collectability. This is the rarest of all the onyx transparent. The color is mint since never been filled with ink and there is (0) corrosion, however the nib has been tipped in the ink and few word has been writing. Most of them including the waterman's i have seen was black hard rubber (bhr) and i have seen only 2 over 55 years. This is not for anyone but again you never know who is watching.