New shifter cables Boardman Air - internal cable guide?

I'm needing to do new shifter cables on a 2013 Boardman Air - the derailleur cables route under bottom bracket like most 'normal' internal cable routing - for the rear they exit through a hole on rear stay and front exit a hole below the front derailleur.

I am pretty sure there is some sort of internal cable hose/routing cable. I emailed Boardman and didn't get a reassuring confirmation - more of a 'yeah, we think that's it'..

Anyone have any experience with these? See attach pictures. TIA