Down here in Louisiana it's usually pretty warm and humid, which means I seldom wear a jacket or sweater. I've tried all sorts of IWB holsters but could never find anything that really hid the fact that I was armed.
I usually resorted to borrowing my wife's S&W 642 because it's the smallest handgun we have and it was easier to conceal.
I received a satisfaction guaranteed, send-no-money-now mail order offer for one of these belly bands and I figured I had nothing to lose.
I was very satisfied. I can now carry my Glock 27 and a spare mag and you would never know it.