This is one of the ONLY 30 key bearings available for the Jeep TJ and TJ Rubicon or any Dana 30 external knuckle. I can confirm that the Alloy USA bolt pattern matches the OEM 5 through 4.5 bolt pattern. My dad is a locksmith and he agreed the tool is top notch. It is installed like a normal bearing. The set was top notch. Auto parts stores do NOT have this item, so it is recommended to have a spare for tires 37" or larger. Left and right are the same, so only one replacement is needed.