There is no doubt in my mind that these moisturising cartridges really help you get an optimum shave and great skin. However the adverts don`t tell you that each one can be gone in 2/3 shaves alone! 5 would last you about 10/15 shaves, but is it money well spent when you shave at least daily? I think it is, beacause these cartridges arn`t exactly as expensive as diamonds, but if you doubt their effectiveness even one bit then trust your instincts and don`t buy them. Mu shaver hasn`t had one of these in it for a long while now simply because of how tiny the ammount of actual gel is, but I am starting to miss their great feeling and I will probably get some in the near future. My advise: if you don`t know them then i wouldn`t advise you get any but if you love them then do.