This one of those files that takes a while to be sure if it works longer term. What I can say after a few listens over a week is that on my test areas (forearms and facial) that shortly after shaving my skin showed small dots of redness that lasted for a few days (nothing very noticeable) to others. At this point, I can only feel a few hairs left on my forearms so that\'s cool. The facial hair seems tougher as I shave daily and I only see patches that are not growing as before. Note that these clear patches are not going away. So I\'m not going to rate this one yet but wanted to give an update.