Retroarms Rotary Chamber- True Centering Unit (TCU)
The True Centering Unit (TCU) is Designed for the Retroarms Rotary Chamber specifically to prevent the hop-up unit from rotating from side to side. This is caused by the manufacturing tolerances of the hop-up installed into the outer barrel. Additionally, the movements of the magazine while shooting may cause the hop-up unit to sway further causing major inconsistencies to your BB trajectory.
Once the TCU is fitted, the Retroarms chamber will be tightly fitted in place and sitting on the true center position to prevent BBs from swerving at a tangent.