Bus Éireann is responsible for the service 40 between Killarney and Cork.
They have some excellent information on their website under their standard terms and conditions of carriage section, Passenger Luggage
. They allow for one medium-sized case, a small hand luggage item free of charge per person. Any additional baggage is dependent on the availability of space and incurs an extra charge.
We hope this helps and that you and your family enjoy their time with us.