Airtech Studios Advanced Hopup Chamber Inner Barrel Ring for Maxx Rotary Hop-up Chamber

"Super snug, definitely recommend this.

"Extremely effective!!!!! Used this on my Maxx unit that's inside my vfc build. Between the tight fit of the vfc upper and lower and add this upgrade part it completely stabilized a prometheus 433mm 6.03mm inner barrel, in the upper receiver. No wobble from the inner barrel at all now.