I have a MIRA Defense PAPR and the battery sled is pretty difficult to get out of the compartment. About a week after getting it I was trying to remove the battery sled and the piece securing the battery compartment cap to the retention lanyard broke. The cap was fine, but was no longer secured to the device so you had to make sure you kept an eye on it when removed.

I reached out to MIRA, but they don't sell replacement caps; so I made one based on their design. It screws on the same as the original, fits the spring inside as well; however on the top is a screw that can be removed or re-printed if broken.