XLIGHTS, and where to buy them?

[Osiris19]

Today I was looking around on YouTube and found a guy who put something called XLIGHTS LEDs in XMODS Nissan GT-R. I have a few questions about them.

1) Are they anymore power efficient than regular LEDs?

2) Can they be run right off the chassis battery, or do they need an external power source?

3) What sizes are they available in?

4) Are they worth getting?

Thanks,
Jared