The HMF Quiet Core is an insert made of 201 Stainless Steel and installs on most HMF exhausts in seconds. It's designed for sound sensitive riding areas and decreases the sound level approximately 3-6dB. 

Quiet Core Fits:

• Peformance Series
• Swamp & Swamp XL Series
• Penland Series (Torque Range Modifier removed)
• Signature X Series