when they were first sold on the 'blister' pac, all the models , and types were printed on the back of the package,,,never saw any other "list" anywhere...and you learn over time that the height differences are "equal" and you can mix and match individual rings to make a "set"......the MInis, and some redhawks , early ones, and the MK II Comp., this height was "even" front and rear...the M-77s , and the Super Redhawks, the front ring is higher than the rear one,,, Off-set, in height........class dismissed........