Looks like an 18g or 20g maybe - I assume the downpipe coming off of the hot side (connects to the back end of the exhaust) doesn't look stock either - no heat shields or stock looking cats?
Here are some good pics - half way down the thread is the VF52 that would have been stock on your car (the new looking one that is marked IHI). There are several distinct differences you can compare better looking at your car - see the difference in the length / orientation where the wastegate actuator connects, different coupling etc. for the compressor output, flatter hotside snail without the seam etc.
VF52 vs 18g