Designed for maximum torque and power across torque curve. Features a durable 16 gauge steel body with a lightweight aluminum rear end cap. Includes U.S.F.S. approved, removable screen-type spark arrestor; replacement spark arrestor sold separately. Bolts on to stock headpipe in minutes. Repackable muffler body. Optional Quiet Core Inserts available separately. Made in the U.S.A..