Ok so I'm bored at work and I just looked up what I ordered thru amain. So the o rings that u need to rebuild the 11h carb on the 12tz is as follows by part number:

2X OSM27881820.
1x OSM22615000.
2X OSM22781800.

Each one comes in a pack of two and that will be plenty to rebuild your carb with a couple left over. The 11h only uses 3 different o rings according to the manual. Large, small, and the o ring between the carb and the crank case. So there u go! That's all u need. Otherwise that link I posted above has the actual hard parts of the carb too.