I looked at this and thought I recognised it as Osborn Titanic. Then I went out to the shed and got my old Titanic chuck out of its box and realised the collets I've got aren't one piece like this one, though I'm pretty sure this would fit. Looking on the web shows several different types of Titanic chucks, including one which uses the same collets as the Posiloc chuck I use all the time. So I 've decided I don't know enough about the different varieties of Titanic chucks to give an answer, but if you google Osborn Titanic you will see something very similar to this. I think there must be several different type of OT chucks just to complicate matters.
Anyone know any more /different?
Rgds Simon