King C. Gillette Neck Razor Cartridges are specially designed replacement blades for precise neck and cheek grooming. This pack contains 3 cartridges compatible with King C. Gillette neck razors. These cartridges are designed to provide a close and comfortable shave specifically for neck and facial areas. For best results, replace cartridge when blades begin to feel dull or every 3-4 weeks depending on frequency of use.