Concept 2 Phase 2 or 3


New Member
I am researching the Concept 2 for my boss. However, he has told me that his Dr. has recommended the Phase 2 or Phase 3. I do not see any mention of a Phase 2 or Phase 3 in relation to the Concept 2. I just see that there are models D and E. Would anyone know what Phase 2 or Phase 3 mean? Also, does anyone know of where I can purchase a used one, besides the usual suspects of ebay, amazon, craigslist, and OfferUp?