Compaction wheels in the Drum style. They have sealed bearings within the drum which eliminates the common issues for older style wheels.
The 12T wheels are 470mm wide and weigh 460Kg, the 20T wheels are 510mm wide and weigh 745Kg and the 30T versions are 570mm wide and 1220Kg.
Note the Axel mounts add additional width. These sizes maximize the pressure your machine can place on the soil being compacted.