Access Hole or Extra Bolt Circle
For Alloy Axles

 
Optional Service
Available when purchasing related Alloy Axle packages

Access Hole
Provides the ability to tighten housing end nuts thru the axle flange
May be required with brake kits using internal parking brake

Or

Extra Bolt Circle
Offers more future wheel options

Note
There is enough room for two bolt patterns and an access hole
Ordering both would double the price