I bought these to try out in my Gem Contour II and Micromatic razors. I figure if I get 10 -14 good shaves they are worth it. I got 12 shaves on my first blade. The first shave was on a two day growth. I felt a little tugging at first, then it went away. The subsequent shaves were all smooth until the 11th and by the time I completed the 12th, I knew it was time to call it quits. I would have given these five stars, but I have found that some Personna products have inconsistent quality (their injector blades and their stainless steel single edge blades). Since I only used one blade so far it wouldn't be fair to give them 5 stars... yet. On the whole the Blue Star blades are a good value. Note: these are not stainless steel blades!
You must wipe them off after each use or they will rust.
As all ways Maggard's service was spectacular with fast shipping!