I've had some issues identifying this brake, and while I do know its wtb and circa late 1980s-early 1990s thats it. Any information would be appreciated. To clarify the parts were not original to the bike frame, as its a 1993 diamondback arrival.
Those brake boosters are definetely by WTB, you can see a logo on third photo. I'd gues that whole assembly is by WTB too, at least google images return very similar results (this post especially, scroll down a bit for a picture).