I have a Mont Blanc knock off - at least I think it is - that I need new piston fillers for. The pen has no writing on it at all except on the nib; "Iridium Point Germany." It used to have the squeeze bag filler that never worked well at all. Some time ago I found a piston filler with the words "Mont Blanc Germany" engraved on the chrome end holding the screw stem. It fits perfectly! I would like to find more of them since this one doesn't fill completely. Can anyone help? Thanks.