My NMTB40 collet chuck is fitted for OZ25 collets, it is branded "STM". It seems to work well, never had an endmill pull out. I've never run a dial on it, I just use it. It came to me on a trade, so there was no cash cost. I'm quite happy with it as I don't otherwise have a collet chuck for the NMTB40 mills. Most of my kit has come to me from the usual "end of the line" sources (Kijiji, auction or diverting someone making a drop off at the scrap dealer) - so I have not standardized on a single/few systems. I think I have 10 different collet systems/sizes - with some intelligent rationalization, one ought to be able to whittle that down to say 5 systems/sizes. However, I work with what I've got and the OZ25 setup has worked fine for me.