This pair of exhaust chamber O-rings is a perfect replacement part for your BETA X Trainer 300 RR. These rings are designed to fit securely and provide a reliable seal for your motorcycle's exhaust system. Made from high-quality materials, they are built to last and withstand the rigours of off-road riding. With a manufacturer part number of 100.43.3.0000, these O-rings are specifically designed for your BETA X Trainer 300 RR. They are suitable for placement on the exhaust system and are compatible with other parts of the motorcycle. Whether you're replacing a damaged or worn-out part, or simply upgrading your motorcycle's exhaust system, these O-rings are a great choice.