* Specifications: ①Pulley Quantity: 1; ②Belt Type: V-Ribbed; ③Outside Diameter: 76(mm); ④Bearing Bore Inside Diameter: 17(mm); ⑤Width: 28(mm). * OE Performance: Perfect match with the original part for sturdy and durable construction. Maintain proper belt tension and rotate smoothly and quietly. * Fit: for Mercedes-Benz C 230 Kompressor 1.8L 2.3L 2002-2005. * Pros: this belt tensioner is made of metal material, which is wearable, durable and scratch-resistant. * Function: a belt tensioner or/and idler pulley is a system that guides the serpentine belt and the timing belt on a car engine. The function of a pulley and a tensioner is to limit the belt slip. The belt tensioner can be mechanic (spring-loaded) or hydraulic.* Situation: If it might help anyone, the motor begin to shake very roughly at idle and even more under load. The shaking would get worst along with a loud squeaking and rattling noise with the AC on and while turning the steering wheel(more load). The noise was coming from the front right area around the AC compressor, super charger, and belt tensioner. I decided to replace the tensioner first since it's the cheaper of the three. Also the belt felt loose and the tensioner seemed jumpy while at idle. Turned out the tensioner was the problem and replacing it with this new Gates tensioner corrected the shaking and noise. Again perfect fit, great product and fast shipping.