Vacuum Bell Therapy will not give you the expected results if you use the wrong device, that's why is so important.
Pectus asymmetry, flared ribs, the device needs to be bigger than the pectus area, the effective vacuum diameter is smaller than the nominal one, and the nipples must be preserved from direct vacuum pressure.
Dr. Belkin is an expert so the margin of error is minimal and you'll also have the right to change the model, even if it's a medical device, in the remote case his advice will not be accurate.
.The distance between the centers of the nipples
The following photos: (without a face for privacy)
1) Photo where the ruler is attached horizontally between the nipples
2) Photo where the ruler is attached vertically in the middle
3) One photo half right/half front
4) One half left/half front
VERTICAL VIEW UP and DOWN
(optional but valuable)
You'll have your response in the shortest amount of time possible, thank you very much :-)