Accessory Silencer for off-road use only. Offers improved tonal quality. Requires specific calibration to guarantee optimum performance. Less otherwise stated Triumph Accessory Silencers do not conform to EPA noise standards. Use on a motorcycle subject to EPA regulations constitutes tampering and is a violation of federal law. These products are designed for closed circuit competition use only. Triumph Accessory Silencers will require a specific tune download, which is available from your authorised Triumph dealer.