The LED-Unit for the Exia and other kits is from Gashapon Toys.
Problem with those is the cover to hold the Batteries in place.
The Screw used to secure the cover in place is one of those(sarcasm) lovely(/sarcasm) screws that strip when you look at them lopsided and don't seem to fit a standard screw-driver.
Yeah like some of those screw in the older MG kits.