Weird, bright Unreal Engline textures - what are these used for?

Hey,

I'm working on a rip of Sunstreaker from the game Transformers Online, which runs on Unreal Engine. I found the grey textures and the bump-maps... but what are these? The models are black and white without them and I'm unsure how they're supposed to be applied. Working in 3DS Max.

First post, sorry if anything attached wrong. Sorry for typo in the title, I don't know how to fix it.