Panasonic WES9013PC Electric Razor Replacement Inner Blade and Outer Foil Set for Men - Replace with true Panasonic parts. It is recommended that you replace the outer foil at least every year to maintain your shaver's cutting performance. Panasonic Replacement Outer Foil and Inner Blade for ES-SL41, ES-LT71-S, ES-LT41-K, ES8103S and older model ES8109S.