So I have been testing personna blades made in the USA. Tonight was my seventh shave with the same blade. The last six shaves were incredibly smooth. Very close shave with no irritation. The seventh shave was still smooth, however It was not as close. I found myself having to make extra passes. The shave on the seventh shave was about the same as my old disposable razors were on the first shave. With my old razors I could only get two uncomfortable shaves. the first DE blades I used were dorco. I got four shaves with those. I'm amazed that I got seven shaves with the personna blade with out razor bumps. The box of 100 will last 700 shaves! For everyday shaving that's close to 2 years of shaves. What a value. I'm so glad I found DE shaving.