Help with rims

[DTM_325]

I just bought some rims a few weeks ago and i think they are 5 series rims and trying to find out for sure.
I took rim off today and saw this...

http://img48.imageshack.us/img48/6938/im0000797hb.jpg

anybody know why its machined and what the offset is?

 

[mpayne]

I just bought some rims a few weeks ago and i think they are 5 series rims and trying to find out for sure.
I took rim off today and saw this...

http://img48.imageshack.us/img48/6938/im0000797hb.jpg

anybody know why its machined and what the offset is?

It was machined to fit a different car. The offset should be around +20.