The Gillette Mach 3 Blades 4S features sharper blades than the Sensor3, engineered to last for 15 comfortable shaves. These razors have a lubrication strip that glides to help protect your skin from redness, and a microfin skin guard that stretches the skin and prepares hair to be cut. Each razor blade refill is designed to fit all Mach3 razors, making it a convenient option for men. This pack includes 4 Mach3 razor blades, with stronger-than-steel blades that stay sharper longer.