Can anyone decipher this Unilug size?

Hi,
I'm looking at an old set of unilug wheels, and I'm not sure I understand the sizing? They appear to be 15X7, but beyond that...

Thanks for any help,
Paul

 

6 lug sizes 5.45 to 5.75.... that's what I read!

 

The 9011010239 looks to be the part number and the numbers behind the 15X7 probably refer to the 5 on 4.5 / 4.75 range of the unilug. The 6 could mean one of many things such as the wheel number, back spacing or finish.