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Going by the first pic, the cover looks like plastic, so it’s probably LEDs. Halogen lamps would need (more) venting holes and/or more “space” inside the housing.
And if your G4s are constantly dying, it’s either “just” crappy quality with overdriven LEDs, or it could also be the housing. Halogens are a bit more heat resistant, so if you don’t have enough ventilation the LEDs just cook themselves to death.
Definitely better than the usual full plastic spool, but IMHO a step back from “true” masterspool refills. I’ve already printed my MS spools, switching in a new refill is easy enough, and I never bother to store an already opened refill without a spool since I store all of my filament in a drybox anyway.