Silencer adaptor for a TM Hi Capa

[Reptile Smile]

Hi all,

I want to put a suppressor (probably a tracer, actually) on my Hi Capa, but not quite sure what I need. Is it the 11mm/14mm converters on eBay? I presume ideally into a metal outer barrel, though that might have to wait for a while.

Or is it something completely different?

Any advice gratefully received.