[mochaccino]

There are other body vacuum pump companies, and some of them list the circumference of the domes/cylinders. The majority would probably fit in NB's tubing, but I can't say for sure. If you expand your search, you might be able to find even larger domes than what NB has.

There are a few issues with domes that are too small. If you fill them out completely from the very beginning, you won't get much suction, which is obviously problem. The only other potential problem is that you might not be able to get a good seal if the fit is awkward, but I have no idea whether the cups need to be directly in contact with your ribcage on all sides in order to form a seal. Maybe, maybe not. I guess there might also be pain issues if the edge of the dome is digging into breast fat, but based on everything I've heard, the opposite seems to be true. It's the people with narrow, bony rib cages (like mine) that find that the domes dig into their axillary nerve and sternum. You're best bet would be to find out which company sells the largest domes/cylinders available. I bet someone on the Noogleberry forum will be able to tell you where to find them.