Each Aztec track cleaning car comes complete with one, two or three rollers depending on model, as specified in the product description.
To add flexibility to your track cleaner, you may wish to purchase an additional roller(s). N scale rollers come in three types: the Cratex® roller, the Sidewinder™ (canvas covered) roller, and the Cobra™ (Handi Wipes® covered) roller.
The Cratex roller must be run “dry” (without any track cleaning fluid). The Sidewinder can be run either dry or with the cleaning fluid of your choice. The Cobra is designed to be run “wet” (with cleaning fluid).