I had to about use a crow bar to get it out of the DX200 case.
This is the Hotfire 900, I bought a replacement early on from FT prior to Hotcig getting after them for the low selling price.
I have a new Fullymax 900 but just used the original that it came with, I'm saving the Fullymax for "other ones".
I think I had better take a look at the installed one come to think of it.
Puffy? (this is the one that I removed)
Edit: So I took a look inside the original enclosure and the pack has no swelling.
There are some slight difference in the enclosures though, the replacement has DX200 on the side. The end of the case where the door slides in is different as well as the block with the power pins, almost the same but different.