The ACDelco Professional, premium aftermarket Subaru V-Ribbed Stretch Belt Installation Tool is required for proper installation to keep from damaging the belt on the 2008-10 Subaru Impreza, Forester, and Outback with 2.5L engines. These vehicles utilize the Stretch Fit belt technology on the A/C compressor drive and it is required to ensure proper installation. Part number 91031. This Subaru V-ribbed stretch belt installation tool meets the performance standards you would expect from ACDelco.