Like I said earlier in the thread, these were my go to (ok only) blade for several months. And in a pinch for mostly single pass shaves I could get by using them. Not sure on two pass shaves. I think I have one or two left and will have to try them again. (I think I have a ST300, a ST301 and even a Derby that remain untried/unused) I could certainly put one in each of the 3 razors I have in rotation and test them.