Fire-rated downlight covers were popular when all downlights used high-temperature halogen globes. They not only protect against fires but also reduce draughts and minimise the number of insects falling through from your roof space.
Nowadays, these downlight covers are no longer needed. This is thanks to modern LED downlight fittings like these usually being:
- Sealed to the roof space (no draughts), and
- IC4 rated (which means they can be abutted and covered with insulation without a downlight cover).