Thanks for the replies. I cannot see any mention of the pipes acting as a reducer but they do taper slightly. Please see attached pics - they might give a clearer picture.
The installation says in the last step:
'8. Connect the hot and cold tail pipes to the water main using a 1/2" BSPx15mm...
Totally newbie question: I have just bought a new kitchen tap (Abobe Altas Monobloc) and it came with 2 copper tail pipes to run from the tap to the water supply. However my current tap is connected using flexi hoses - am I okay to bin off the copper pipes and just use the existing flexi hoses...