Anyone here tried the Pentel Tetras Stylo "disposable fountain pens"?

They sound interesting

"Unique double-sided nib, firm one side, flexible the other for stylish
writing. Smooth flowing liquid ink with a high-tech ink regulator."

I recall trying the older ones and they were a favorite disposable a
few years ago
http://www.euroffice.co.uk/itm_show....tain-Pens-JM20

The Tetras Stylo seems to be a newer and more evolved version
http://www.euroffice.co.uk/itm_show....-Fountain-Pens