Rein OE Quality DL501 dual clutch transmission service kit offers a convenient solution to the Audi / Porsche recommended 40,000 to 60,000 mile interval filter and fluid service. The DL501 transmission is structurally divided into two compartments with two different fluid specifications. This Rein DL501 transmission service kit is specifically designed to service the hydraulic circuit and wet clutch filters. The included OEM clutch filter cartridge is the first line of defense against free floating clutch debris, and it must be changed at Audi / Porsche specified intervals for maximum longevity of the dual clutch gearbox. CRP recommends using the OE or Pentosin FFL-2 high-performance DSG fluid for this service.