WELURE 2-Pack ES9943 Men's Electric Razor Replacement Cutters Outer Foil for Panasonic ES9943 ES3800 ES3830 ES3831 ES3832 ES3833 Men's Shaver Replacement Compatible for Panasonic Models. Within 18 months, your shaver will cut an average of 6,000,000 hairs. In accomplishing this substantial task, the cutting parts will gradually wear out and your shave may become less close and comfortable. That's why recommends changing your shaver’s foil and cutter block every 18 months to maintain your shaver’s maximum performance. For an efficient shave every day You will Get: 2-Pack Electric Razor Replacement Cutters Outer Foil