The JACK™ system was designed to answer the demand for an affordable, high performance HPA (High Pressure Air) conversion for AEG's.
http://www.airsplat.com/polarstarjac...

The system is a dropin cylinder replacement that is universally compatible with a wide range of gearbox versions that have centerline 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.