Gillette Mach3. They aren't big slits but they are present. I won't open a sealed item to remove them.
Gillette Mach3 15 Refill Cartridges
Gillette Mach3 8 Refill Blade Cartridges Fits All Mach3 Handles
Gillette Mach3 8 Refill Cartridges Stainless Steel Compatible with Mach3
Gillette Mach3 15 Stainless Steel Razor Cartridges For Gillette Razors
Gillette Mach3 15 Cartridges
