Up for sale is FMF ULTRA QUIET F4.1 RCT QUIET CORE S/A INSERT 40689. The vendor part number is 40689. Please read title to know what you are getting. The catalog decription.... is No flames. Even Less noise.1-1/2" Quiet Insert with Spark Arrestor for late 2021 & 2022 4.1 RCT mufflers0.3 lbs.