This is a complete replacement of the E1 operating system. The new engine includes a redesigned bolt, larger firing chamber, and tool free back cap removal. Get more shots per tank, and break less paint because your marker is running at a lower pressure.
Dangerous Power E1 Bolt Upgrade
Less Bolt Weight = Less Kick
Use Less Air Per Shot = More Shots Per Tank
Lower Dwell Settings
More shots per tank + Lower operating pressures + Lower dwell = More Wins!