MonteVerde® Threaded Fountain Pen Ink Converter [Schmidt K6/K5 style]….fits Mega Ink Ball Series & others

K5 differs from K6 in that you do not have the three concentric circles at the tip of the refill.
However, they fit the same pens.

fits the Mega Ink Ball Series of MonteVerde®. Manufacturer states that this converter may also fit the following: Ancora®, Aurora®, Bexley®, Conklin®, Conway Stewart®,David Oscarson®, Delta®, Dunhill®, Faber Castell®, Krone®, Laban®, Lepine®, Libelle®, Marlen®, Michael’s Fat Boy, Nettuno, Pelikan®, Porsche Design®, Retro 51®, Stipula®, Taccia®, Think Pens®, Tibaldi®, Visconti, Waterford®, Waterman® and Parker®.