A Hammer Weight to add to your FX Impact MK1, to help open the valve at higher regulator pressures. This Hammer Weight is slightly larger than the Hammer Weight now included with the FX Impact Power Plenum. Can add up to about 60 FPS, based on previous regulator settings and caliber. Replaces the plastic Spring Guide on Pre-Power Plenum models.
Note: You might will have to close your valve adjuster completely when re-attaching an air bottle to ensure the valve pin properly seats, due to the extended length of the hammer assembly.
Not recommended if you already have the FX Impact Power Plenum.