Indeed it is very useful, it is obvious, having already experienced twice; but frankly, for double the price, you have the razor Braun cruZer4 'brand new: this is not it worth the trouble to think twice? anyway, I did not hesitate for a moment and just recently, I just bought this razor and I have the feeling of having made the right choice WIDELY! A conclusion is shaped call: gentlemen designers and marketers, be reasonable and consistent, and lower the price of your spare parts .. thank you.