PolarStar Airsoft JACK V2 M4 / M16 Electro-Pneumatic Gearbox Conversion Kit

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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. 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.

JACK has only 1 moving part, the nozzle, which acts as its own poppet valve which is piloted by the solenoid. With the exception of the poppet being integral to the nozzle, the valve is similar to the poppet valve used in the previously released Fusion Engine and is what gives JACK its signature muzzle report. The system itself only has 6 parts and can be completely disassembled by hand in a matter of seconds so the system is very reliable and easy to maintain.Just like all other PolarStar HPA conversions, JACK also allows for easy velocity adjustment.

Using a standard M4 as an example, velocity can be adjusted from below 280fps and up to approximately 500fps with a .20g BB. This can be done simply by adjusting input pressure and poppet dwell to fine tune your rifles velocity in increments of just a few FPS at a time. Maximum velocity potential of the system will vary depending upon the barrels length and tightness of the bore. Longer and tighter barrels will yield a higher velocity while shorter or wider barrels will be yield a lower velocity.

As with all of PolarStar's electro-pneumatic conversion kits, you can quickly change and adjust key functions of JACK via the on-board FCU (Fire Control Unit) which is no bigger than an AEG's MOSFET and can easily fit inside of a rifles battery compartment along with a small Li-po battery. Using the FCU's five position joystick and LCD display you will be able to easily and precisely adjust such functions as the systems cyclic rate, fire modes and poppet dwell on the fly.


    • Designed, manufactured and built in the U.S.A..
    • Assembled from CNC machined aluminum components.
    • Rate of Fire: Adjustable between 1-30+ rounds per second
    • Operating Pressure: 80 - 120 PSI
    • Velocity (with 375mm inner barrel @ 120 PSI): 500FPS with .20g BBs
    • Universal cylinder design is compatible with numerous gearbox versions.
    • Optimized flow profile, firing point and flow path promotes superior shot consistency and accuracy.
    • Capable of functioning in damp and sub-freezing climates without affecting performance or reliability.
    • User select-able Semi/Full Auto, Semi Auto Only and variable 2 to 9 round burst modes.
    • Independently adjustable velocity and cyclic rate.
    • Auto Switch mode allows for proper selector configuration for specific models.
    • Easy to use Fire Control Unit (FCU) with LCD display and five position joystick.
    • Instantaneous trigger response for faster and more responsive engagement.
    • Compatible with Version 2 TM-style M4 / M16 AEG Gearboxes

      Package Includes:

        • PolarStar Jack V2
        • PolarStar F1 Fire Control Unit
        • PolarStar Trigger Board

        **NOTE** FCU Battery, Air Rig System and Air Line are NOT included

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