I've been using Norelco rotary electric shavers all my life and this is the first time I've ever purchased replacement heads. What a surprise to find out it's just like getting a brand new shaver! My old Norelco was not performing as well as it used to and I wondered if it was time to upgrade to something "better" - whatever that might be. I decided just to save some bucks and try replacing the heads (just like they advise). Suddenly, all the little complaints I had about the performance of my old Norelco disappeared. I had a new shaver with the top notch performance I used to get. Try replacing the heads before you fork out big bucks for all the fancy, non-esssential "features" they now build into high priced electric shavers.