The problem is this is dependent upon density as well. A thinner unit is going to act different than a thicker one.

The thing with these full caps is that if you get one that holds density fairly well (as this particular one has) all you have to do is keep getting hair added here and there and these things will last you awhile.

I'm actually still on my first two full caps that I stared wearing I think it was February 1st. Knock one month off that for when I was wearing a skin perimeter unit that had to go back just to preserve the one good one I had (the other needed a little hair added), but with hair adds in these two units I am going on 7.5 months, and I think I can squeeze another 6 weeks between the two of them. That makes 9 solid months for two pieces, one of which sheds like crazy. If I had two units with good hair I'll bet I could get a solid year with a couple of touch ups.

I have four more on the way, so I might throw caution to the wind once I get one or two of them sorted out.