Hi Age,
I'm a little confused about what you are asking for.
CPT, or chest physical therapy, is the actual airway clearance done after nebulizers to loosen the mucus in the lungs, making it easier to cough up. It is not done with an oxygen mask. Most people use either manual cpt (having another person pat the different lobes of the lungs), therapy vest (which shakes all of the lobes simultaneously), or a device such as the flutter or acapella.
I think what you are asking for is a mask for nebulizer treatments. Am I right? These do look very similar to oxygen masks and are held over your infants nose and mouth while the medication is running through the nebulizer. They are usually available with your neb cup and tubing, wherever you purchase those. Some pharmacies, like CF Services, will send you your tubing, nebs, and masks. Others, like Express Scripts, will not send neb supplies with your meds and you have to purchase them from a medical supply company.
On a side note...always remember that if you are ordering your nebs separately from your meds, make sure you use the nebulizers and supplies recommended for the specific meds you are taking. ie...pulmozyme should always be taken with the Pari LC nebulizers.
I know this is all alot of information, but you can always come here with questions like this. Whenever I have a question I depend on the knowledge of those on this site and usually have an answer right away.
Good luck!