Pack lasts up to 5 mos (based on average days' use per cartridge). Lubricating strip. Advanced pivoting head (vs. Gillette Custom Plus/Sensor2 disposable). Superior cartridge geometry (vs. Gillette Custom Plus/Sensor2 disposable). Microfin skin guard. Individually spring mounted blades. Nano-thin blades. Gillette: The best a man can get. All Mach3 cartridges can be used on all Mach3 razors. Comments? 1-800-GILLETTE; www.Gillette.com. Patents: www.pg.com/patents.