I think ptgarcia was looking for these specs......

The OEM forged and polished aluminum wheels have the following dimensions:
Size: 17"x8"
Offset: 43.18mm (1.700") positive
Backspace: 6.25"

Hummer H2 wheels have the following dimensions:
Size: 17"x8.5"
Offset: 18mm (0.709") positive
Backspace: 5.563"

Backspace is the measurement from the wheel mounting face to the outer most portion of the rim lip on the inboard side of the wheel.

Offset is the measurement from the wheel mounting face to the centerline of the wheels width. Positive offset pushes the mounting face outboard of the wheel centerline. Negative offset pushes the mounting face inboard of the wheel centerline.

Backspace is the more important number to be concerned with when sourcing aftermarket wheels, expecially when you go wider than OEM.