DO NOT ORDER THIS PART UNLESS YOU ALREADY HAVE ONE OF OUR FRAME MOUNTED LOWERS.
The Underworld Arms Cerberus Upper is intended for customers who have a Gen 3 MAC with full length frame and windowed slide and already own one of our frame mounted compensators and want to swap to this new style upper.
This compensator upper features two large top ports and four smaller angled side ports.
On most builds recoil spring tuning WILL be required, a spring in the 8-10lbs range will usually be necessary for proper function unless heavy +P loads are being used.
