JX-85 units were built for mobile air filtering usually used on space stations or in dome settlements built on a planet that is under going terraforming. These drones are able to purify the air with their filtering equipment attached to the arm and back. The process happens in two steps, first the air gets sucked into the arm compartment where the bigger particles get stuck on specific filters, from there the air travels to the backpack where the more precise filtering/purification can happen. Often these robots are referred to as janitors because they are also tasked with keeping everything clean as much as possible.
Well, this fella didn't get too much of a change but just enough. Haven't touched him since 2010, not many MOC of mine can say that, that their overall looked has not been changed for so long. None the less I still like this little guy, and thought I give it a few newer parts, plus the original look of the backpack started to look very outdated/clunky and required a better, more fitting look.