I asked when I was buying them Al, not sure if this was the correct answer but in reply to my question about curves and the different letters that they were, he replied these were B curve and that denoted the tripping time, is that correct. As far as I could gather B is ok for domestic use with the higher letters required for commercial use etc.
From what I've read they trip at 3-5 times the current (In), so a 16a would trip at 48-80a, does that sound right?