Replacement Inner Blades & Outer Foil set compatible with Panasonic ARC4 shavers: ES8243AA Replace Blades and Foils for an Optimal Shaving Performance: Over time, foils on your Panasonic shaver will wear too thin and blades will become dulled and pitted. Replacing blades and foil once every 1-2 years ensures a smooth, comfortable shave Outer Foil System for an Efficient Shave: Micro-thin foils use unique shaving elements that work in tandem to cut through hair with ease; designed with micro-thin, arched hypoallergenic stainless-steel to prevent skin irritation and maximize comfort High-Quality Inner Blades: Forged from premium Japanese stainless steel and precision-honed to an ultra-sharp 30-degree cutting edge to cut hair cleanly at the base Installs in Seconds: Blades and foils are designed to custom fit your Panasonic shaver model. Simply remove the worn blade and foils and snap the new ones into place