New PSR Manual Camchain Tensioner, designed to replace the unreliable OEM Unit. Racers know that you can not trust high performance motors to automatic cam chain adjusters. Easy to install, the manual tensioner can not back out allowing the cam chain to jump the sprockets as the auto adjusters have been known to do. The PSR Pro Series manual adjuster replaces the factory BMW tensioner.The unique design features a CNC-machined aluminum body, stainless hardware, and an adjuster that uses a 4mm hex wrench for easy access in tight conditions.