I have a Weck hair shaper and it does use the Personna blades and it is the same general blade as the injector blades in thickness and having the metal folded over the top, but the blade length is not the same. It is longer than the regular injector blades. I tried the Weck, the Parker SR1 and the Feather SS RG copy, the CJB and had trouble getting a safe shave with any of them. After trying those I took some of the advice from other straight razor users and bought a straight razor. I still nick myself in learning, but not as bad as with the shavettes. They get close...but too close. I get raw skin with them. I'm sure after a certain amount of time, I could learn to use the shavette better, but much prefer the straight.