Because of to their design and style and how the oslltcaiing blades are positioned, they are capable to develop outstanding shaving benefits. Cleaning cartridges should be replaced every month or two (though we may be up to six weeks), which can make you a bit expensive for some people.On the back of the card that comes with the razor, it states that you should, "Change the cartridge when empty holes start to appear in the gel reservoir".Review my web page ::