From "Honest John" on the web
Quote "
The the 6 defines the width (in inches) and the J defines the shape of the cross section of the wheel rim - the area where the tyre sits. It does not define the PCD of the bolt holes, wheel offset or anything else, so you can't assume another 6J wheel will fit. J is one of the most common sections,but there are others.
Regards
John S " unquote
This seems to answer the question quite well
H2 appears to mean double hump (see link below)
If you want info on wheel types go here :-
http://www.tyreline.com/wheel_tyre_i...measurment.htm
If you want info on tyre markings go here :-
http://www.tyreline.com/wheel_tyre_i...e_markings.htm
