3-Blade System: The core of the Mach3 design is its three progressively aligned blades. This system is engineered to cut hair closer to the skin with each pass, aiming for a smooth and comfortable shave with fewer strokes.

Lubrication Strip: Each blade cartridge is equipped with a lubrication strip that helps the razor glide smoothly over the skin, reducing friction and protecting against irritation. The strip fades to white over time, serving as an indicator that the blade needs to be replaced for optimal performance.

Microfin Skin Guard: The cartridge head features a series of soft microfins that stretch and smooth the skin before the blades pass over it. This helps to prepare the hair for cutting, resulting in a more even and comfortable shave.

Durability and Compatibility: According to Gillette, a single Mach3 blade is designed to provide up to 15 comfortable shaves. A major advantage of the Mach3 system is its cross-compatibility: these standard Mach3 blade refills will fit all Gillette Mach3, Mach3 Turbo, and Mach3 Sensitive handles.

Packaging: The "4S" simply denotes the pack size, indicating that you are getting four blade cartridges. This is a popular size for consumers who want to have a few spare blades on hand without buying a larger bulk pack.