Don't be alarmed mate. By adjusting your piece it is only little things, eg the lace is resting on your ears so you cut a little of the lace around it to fit properly. It isn't what you think mate. My template was followed to the T which it had to be as I had Poly sides and I am hoping the French lace one will be the same. JRob is right by suggesting buying 2, that way you always have one on and one off.