You can take one item of hand luggage, as long as you can ensure to store it safely in your seating area. Depending on availability suitcases can also be placed in the space next to the door in Hamburg or in the luggage rack in the back of the MOIA in Hanover.
Mutual consideration between all passengers is key in order to make everybody on board comfortable traveling with luggage in the MOIA. But please be aware that in the end the driver decides about what can be taken on the trip with MOIA and what can't.
For mobility assistance equipment please follow the link.