As Dan says. In addition, please look for YT videos from Thorn/SJSC detailing the oil change procedures. I split the 25 mL cleaning oil in half and do twice in attempt to improve the flush. A side note, best to buy a large amount of Rohloff fluids rather than using the single 25 mL volumes. Our tandem Rohloff is going strong after 20,000 miles heavily loaded for touring. A Rohloff on a touring tandem is outstanding!