FMF 4 Stroke Q4 HEX - Slip OnQ4 HEX: FMF is the leader in high performance quiet technology and the Q4 HEX is the next evolution in offroad exhaust. The Q4 HEX silencer employs intricate chambers, baffles and proprietary multi stage packing material making it the best performing quiet muffler available. With the Q4 HEX you dont need to hear the power, just feel the power! Less sound equals more ground Meets USFS and FIM World Enduro sound regulations Power gains throughout the