Don't get the HR-150, for treestand hunting you want the 200. It produces something like 50% more ozone, which you need. They will work in winds up to about 25 mph. The new units on a hard downward angle do an incredible job on zero to 25 mph winds. We've learned that with 2 units in a tree (filming), as the wind dies to nothing, we point the units in oposite directions on hard downward angles and they work 360 degree's around the tree. They produce so much ozone that with zero wind it completely saturates the entire area around your stand to the point that NO human scent get's through.
Yeah, most guys want 2 batteries to last longer.
Yes, Ozonic's the company plans on addressing the safety issue by using equipment to test the content of ozone in different blinds (all set-ups) proving beyond a reasonable doubt that they are indeed safe.
I don't care what kind of ozone it is, it works!