Which Kensington power tip for Dell E5500?

Hi,

I have a latitude E5500. It uses a 19.5V power brick.

I also have a 120W Kensington power adapter and would like to acquire a power tip to use with the Dell.

Can anyone tell me which tip to use, is the N19 the right one?

And would you also know where to obtain one of those?

Thanks, Ton