What converter is it?

[kolla]

but probably pretty rare to see one today.  

Most (if not all) professional networking gear still comes with support for console on RS232, and those use either DB9 or RJ45 as plug.
The equivalent of the above adapter is a cable with DB9 in one end and RJ45 in the other end, known as a rollover cable.

[kolla]

Comes with, yes.  But how many people still use it? :roflmao:

Well, I know we use it, got an "octopus" server on every location with rs232 console access to all network gear, it's quite normal I'd say.

[kolla]

Thanks, then it's not specific/useful for amiga? =/

Nope, not really. Amiga has a custom DB25 serial port anyways