Crye Precision asked STS to design a Zombie themed gun for a charity auction (before zombies were cool), This product was designed as a joke and afterthought the very day the rifle was being driven to SHOT Show, turned out, the Muzzle Thumper is what everyone loved most!  The Muzzle Thumper reduces recoil energy transferred to the shooter.  Prongs are designed to deflate tires, break glass and muzzle thump zombies, the Muzzle Thumper has been tested on two of the three, waiting for the third #bringondemZombies.   

(FYI: The STS Zombie themed rifle fetched $18,000 for the Unit Scholarship Fund)

• 1/2-28 RH Threads
• Designed for 5.56 or smaller bores
• Comes with Crush Washer