FPS Boost AEG compress ring x4

This rings are used to pre-compress the spring in order to cause a slight increase on fps.

Insert the rings on the piston. Accumulate as many rings as you want, in order to precisely control your fps.

It comes with 4 rings, giving you the possibility to go from 1mm to 11mm of compression. It should give a variation of 1 to 20 fps

Best if printed in polished material as it is smoother. You can also smooth it when received.