The Monster Rounds produce that deep and mellow rumble that wins the hearts of many touring riders. Perfect for enjoying your stereo on the highway, Monster Rounds feature blue-proof technology and a CNC-machined billet end-cap for an impeccable appearance.; ; Produces that deep and mellow rumble that's winning the hearts and minds of touring riders who put in the long distance miles Perfect for enjoying your stereo on the highway Blue-proof technology CNC-machined billet end-cap for an impeccable appearance Full Coverage Heat Shields