HKS Timing Belt for Subaru EJ20 / EJ25 Engines SpecificationsHKS timing belts are far stronger than OEM belts and are designed for highly tuned engines that can reach high RPMs with quick rotation speed variations. Made from the same fibres used in bulletproof vests HKS belts don't fray over time and guarantee excellent resistance to high temperatures and strain.When it comes to Japanese vehicles HKS are one of the most recommended brands with more than 40 years experience in engine tuning and are very rarely matched by the competition.