AP02 Transfer Case Chain 42 links for ML-Class W164, GL-Class X164, R-Class W251, and R350 4MATIC.Compatible with transfer case part numbers HV091, HV-091, 2512800800, A2512800800, 2512800900, and A2512800900.Fits Steyr single-speed transfer cases on model years 2003 onward for W163, 2005 onward for W164, 2006–2012 for X164, and 2007–2011 for W251 R-Class (R320, R350, R550).Does not fit non-US models equipped with off-road package two-speed transfer cases.Compatible with GL-Class X164 GL320, GL350, GL350 BlueTEC, GL420, GL450, GL500; M-Class W164 ML280, ML300, ML320, ML350; M-Class W166 ML250 BlueTEC, ML350, ML350 BlueTEC, ML400, ML500; and R-Class W251 R320, R350, R550.Before purchasing, verify your vehicle's part number matches HV091, HV-091, 2512800800, A2512800800, 2512800900, or A2512800900.