Two-month supply of 5-blade cartridges to be used exclusively with Jack Black 5-Blade Razor. Blades should be replaced after every fourth or fifth use.
Eight 5-blade cartridges included.
Replace cartridges after every fourth or fifth shave. But when in doubt, throw it out. To replace, simply push, with the blades facing away from your finger, until the cartridge becomes dislodged. Slide into cartridge case until you hear a click.