HKS Slide Cam Pulley RB Exhaust 1989-2002 Nissan Skyline GT-R (RB26DETT)SLIDE CAM PULLEY Reviewing the material and design has allowed for a stronger and lighter unit. Highly durable and lightweight pulley Using a super light duralumin (A2014) as its main material that the strength has increased by 50% and hardness by 30% (over previous version). This change in material has allowed the design change that has also allowed the unit to be substantially lighter (10% less load on RB engines) and increasing the engine