What RF connector is this?

Hi Folks,

I'm trying to add an external (2.4 GHz) aerial to the Fritz!Box 7530:

From the third link (photo) above, there's RF test points next to what I assume to be the 2.4GHz aerial on the left and the 5GHz aerial on the right (assuming the larger to be the 2.4GHz).

I got an IPEX-K to RP-SMA pigtail not realising that the test points aren't IPEX but something else:

What they are I don't know, which is the reason for the post. They're described as an 'RF Switch' in some pictures here:
And, look like they're one of these:
But, have a diameter of about 1.25mm

So, my question is, what connects to them - is there a 'what ever it is' to SMA pigtail? Would it be one of these:

Should I be getting something of better quality than I'm likely to pick-up from eBay if I want to avoid significant signal loss?

Many thanks