I have been trying to scourge information if Pentel Energel refill will fit Lamy Swift body. I have found out that it will fit Pilot G2 refill if you modify the refill by cutting it from the end. According to this epic chart if G2 refill fits then Energel refill will most likely fit. Many other pens that take G2 will also take Energel refill like Retro 51 Tornado. I have found however 2 comments that Energel refill does not fit Swift. One from reddit and one from a blog where the guy says G2 fits, but it is complete mystery why Energel does not fit. Has anyone tried this combination? What could be the probem? I do not have G2 refill in my hand so I can't directly compare them, but judging from pictures there is a different after gel reservoir. G2 has a longer, I don't know what to call it. Thick part? That problem should be fixable with o-ring spacers like you would have to do for Lamy 2000 rollerball and Jetstream combo. Am I missing something obvious here? I don't really see any reason why Energel would not fit Swift.