They are much larger than regular inside cabins. Room enough for a wheelchair to maneuver around the beds.
The shower in the bathroom has a seat s you don't hae to stand to shower, and there's no lip at the bottom either.
Therefore water will spread out on the bathroom floor. Nice for the handicap, not as nice for non handicap passengers.
If you want to book one, I highly suggest doing so early. NCL will sell these cabins to fully able passengers as final payment date approaches, and there is a limited number of them aboard NCL ships.
I use a wheelchair and booked a cruise that will occur in October on the NCL Jewel. NCL asked for a letter from my doctor confirming that I am handicapped and need the handicap accessible cabin before they would allow me to confirm my reservation.