1. Your BC's inflator hose is long enough to reach your mouth easily.
AND
2. Your BC has MULTIPLE, ACCESSIBLE DUMPS and you have to rely on NEITHER the inflator dump OR the shoulder attached to the corrugated hose to dump air on ascent.
THEN the Air2 is acceptable.
On a Scubapro Knighthawk, for example, it has a RIGHT shoulder dump, a RIGHT bottom dump, AND a corrugated dump (in addition to the regular inflator button dump)
It is therefore ok, IMHO, to use with an Air2.
However, a BC that has no top dump on the right side is potentially dangerous to use with an Air2. You may have to remove the Air2 from your mouth to make a BC air adjustment, or you my have to pull on the corrugated hose (which I DO NOT LIKE as a dump anyway - putting that kind of stress on a BC is not a good idea, and if the hose or elbow separates you'll find out why!)
I had an Air2. I sold it. It was a perfectly-acceptably breathing reg (pretty much like an R190), but I moved from a regular BC to a BP+Wing and was pretty-much assimilated
AND
2. Your BC has MULTIPLE, ACCESSIBLE DUMPS and you have to rely on NEITHER the inflator dump OR the shoulder attached to the corrugated hose to dump air on ascent.
THEN the Air2 is acceptable.
On a Scubapro Knighthawk, for example, it has a RIGHT shoulder dump, a RIGHT bottom dump, AND a corrugated dump (in addition to the regular inflator button dump)
It is therefore ok, IMHO, to use with an Air2.
However, a BC that has no top dump on the right side is potentially dangerous to use with an Air2. You may have to remove the Air2 from your mouth to make a BC air adjustment, or you my have to pull on the corrugated hose (which I DO NOT LIKE as a dump anyway - putting that kind of stress on a BC is not a good idea, and if the hose or elbow separates you'll find out why!)
I had an Air2. I sold it. It was a perfectly-acceptably breathing reg (pretty much like an R190), but I moved from a regular BC to a BP+Wing and was pretty-much assimilated