The JACK system was designed to answer the demand for an affordable, high performance HPA (High Pressure Air) conversion for AEG’s. The system is a drop-in cylinder replacement that is universally compatible with a wide range of gearbox versions that have center-line nozzles.
Similar to its sister product, the F1, it replaces the original gearbox components with a programmable pneumatic system allowing for higher performance and greater reliability over a gear driven system. Although economically priced, JACK still retains the same performance and quality you have come to expect from PolarStar products. – See more at: http://polarstarairsoft.com/products/jack.html#sthash.wxlKXiXv.dpuf
Velocity: 500FPS w/ .20g @ 120psi.
The Jack allows for easy velocity adjustment. Using a standard M4 as an example, velocity can be adjusted from below 100fps and up to approximately 500fps with a .20g BB. Longer barrels will increase the maximum FPS while shorter barrels will decrease it.
The maximum cyclic rate of the Jack is affected by several factors, however, 30 rounds per second is a conservative number. Most configurations will exceed this easily.
Air Efficiency: 1200 shots from 13/3000 @ 1.5J (80PSI w/ .28g)
The JACK is extrememly efficient. The patent pending design of the F1 allows for the most direct air path to the nozzle with minimum dead volume resulting in better flow, faster response and less air used per shot. Using a stock VFC M4 as a test platform, the JACK was able to fire approximately 1200 rounds for a 13ci/3000psi cylinder before pressure dropped below regulated output.