The straight through design of the spark arrestor canister and the performance flow stainless steel end cap ensures strength, durability and most importantly, track and trail proven unrestricted power The 2.1 utilizes a shape inspired by the 4.1 system Utilizes exclusive FMF "Turbine Dampening System" U.S. Forest Service legal status. MUFFLER P-CORE 2.1 S/A
