See what I mean about the name? The sticker on the car has at least five letter H's in the name.
Most roller coasters have sets of wheels above the track, below the track, and either between the rails or on the outside edges of the track. This particular type of car has large flanged plastic wheels that sit above as well as inside of the tubular steel track. There are tiny rollers mounted underneath the rails also, but they are not very visible in this picture.