You can find this out very easily by yourself. Unscrew the small (but quite solid) ring at the bottom of the microphone body--the XLR connector of the microphone comes out through this ring--and remove it. Then carefully slide the sleeve off from the body of the microphone.

The original U 87 had a compartment to hold two narrow batteries. There was also a battery meter beneath it, plus a switch for battery vs. external powering. Those parts occupied one entire side, i.e. half, of the space in the microphone's "body" (amplifier).

If your microphone doesn't have those features, and if there is also no vacuum tube, then you have a U 87Ai.

--best regards (I would imagine that Brazil is a wonderful country in which to be a recording engineer ...)