Dyson sell the adaptor for like £3 I think, roughly it's got a click fit for the turbine head and the end of the adaptor has what the DC19 tools have for your DC19
If you mean
this one, it will fit a 19T2 head probably, but that wont connect to a standard DC19 I think, as they have a unique tool fitting. Although I haven't tried that adaptor on a standard DC19, but I can. Cylinder machines are always problematical like this.
Another alternative (and the best one) is changing the socket end on the turbine head at the swivelling elbow, assuming you have the old one and the new one, we do that quite often.