The PDI W Hold Chamber Packing (Bucking) has a unique W hold pattern nub inside the bucking that allows for a more even hop than traditional buckings resulting in greater accuracy. The W Hold bucking also comes with 2 additional external air seal ribs that help stabilize and seal your bucking to your hop unit for increased efficiency. Bucking is considered a soft bucking that is made out of a Nitrile rubber with 50 durameter hardness.
This specific bucking is meant for AEGs or guns that accept AEG Hop Up buckings. It is compatible with Toyko Marui M14 Hop Units provided you cut the bucking down to fit.