Aeon Pro (not X) Spring Constrainer Cap

The sub 130FPS Aeon Pro spring sold on OOD's website has an OD that is significantly smaller than the stock spring. This allows the modded spring to move around freely, and sometimes block the motion of the catch rod. This spring cap has a ring which constrains the spring along its ID and prevents it from blocking the catch. 

I do not know if this fits on the Aeon Pro X or if that blaster uses the same system at all.

You may need to file the inside of the hole to allow the catch rod to exit the spring cap, depending on your printer tolerances.