Each of these refill cartridges feature a unique optimal shave indicator strip which fades to white as the razor performance is diminished. These cartridges come in a pack of three eight-count boxes.Number in pack: 8Number of packs:3 24 total Number of blades per razor: 3Optimal shave indicator strip: Fades to white as razor performance is diminishedLubrastrip glides easily over the skinUniquely shaped non-slip rubber handle for control and maneuverabilitySoft protective microfins help protect the skin from nicks and cutsAll Mach3 handles fit all sensor blades Due to manufacturer packaging changes, product packaging may vary from image shown.