Quiet Insert by FMF USA. This Quiet Insert comes stock in all new FMF Q4 mufflers. If you lost yours, this is the replacement you need. It will fit Q4, Q4 Hex, Powercore and Powercore Hex mufflers. It will reduce the sound rating of the Power Core models, from about 99db down to about 96db. Please choose the correct insert for your muffler. If you are unsure of the year your muffler was manufactured you can easily identify visually which insert you need. Pre 21′ installs using one small screw. 21′ to current installs using a spiral retaining ring. Yah !! lets keep it quite and not upset the farmers. !
