This product is a genuine Porsche disc brake caliper piston seal designed for the rear brakes of the Porsche 911 model. The part number is 99135291780. It is made with high-quality materials to ensure optimal performance and durability. This seal is an essential component of the brake system, helping to maintain proper pressure and prevent leaks. It is specifically designed for use in the Porsche 911 and is an authentic replacement part from the manufacturer.