If you choose to install this high-power valve, please make sure to use darts that are compatible with the higher power valve. They will say "reinforced" on the box. 

Specifications:

• Muzzle Velocity (Experimental High Power Valve): 398 FPS
• Shot Energy (Experimental High Power Valve): 7.6 ft-lb / 10.31 J

Standard valve performance by Comparison: 

• Muzzle Velocity (Standard Valve): 308 FPS
• Shot Energy (Standard Valve): 4.55 ft-lbs / 6.17 J