The latest OEM Subaru tensioners work well for mild performance applications, but when used on vehicles with sequential transmissions or on high-revving engines, the tensioner may lose its ability to control the belt. This would, in turn, cause the engine to skip time. If your engine skips time the repair might be as simple as resetting the belt. However, in some cases, this can cause catastrophic engine failure. In the past few years, our Subaru GD STI road-race car that uses a sequential transmission skipped time several times. This led us to develop a tensioner that would hold the belt tightly in place and accurately control timing. After considerable testing and proving on that STI road-race car, we performed testing on several other road-race and drag applications to further prove the product. With this tensioner installed the problem was solved. We experienced no further instances of timing belt skip. The IAG "WRC Style" V2 Tensioner uses a combination of proven parts from older Subaru vehicles and an additional roller to control belt timing and tension. Made from billet aluminum, the base is CNC machined in-house and anodized black for corrosion protection. IAG is not only a manufacturer but also a service facility with extensive experience with timing rollers and idlers. Not all rollers are created equal and some fail prematurely. The IAG "WRC Style" V2 Tensioner uses NTN OEM style rollers to ensure the reliability of the product. We do not recommend the use of any other brand roller with this product besides Subaru OEM, which comes at a substantially higher cost.