This a factory right rear Taillight TailLamp Rear Brake Light lens assembly that was made in Germany by BMW.  It also includes installation instructions (in German) and is packed in the original shipping box.  It has the small BMW logo in the lens and should not to be confused with the cheap Chinese knockoffs or used lenses that may have chips or scratches. According to the instructions, it fits the “3-er coupe and cabrio (E36), 3B; and M3 (E36), M3B”  

More specifically, detailed charts for lenses that appear to be the same and also for sale on ebay indicate that it fits:

1993-1995 BMW 325iC E36 
1992-1995 BMW 325is E36 
1998-1999 BMW 323is E36 
1998-1999 BMW 323iC E36 
1996-1999 BMW 328is E36 
1996-1999 BMW 328iC E36 
1995 BMW M3 B30 E36 
1996-1999 BMW M3 B32 2-Door E36

I’ve included close-ups of both the BMW OEM instructions and parts of the lens that have serial numbers on them so you can compare them to those on your lens in order to assure yourself that this is the correct model lens.