The engine of your HPA system is the drop in kit you choose. These drop in kits can either replace the gearbox of your AEG entirely, or replace the internal components of your gearbox. Find great options like the Polarstar Jack and Polarstar F2 kits here!
    4 products
    PolarStar JACK HPA Conversion Kit V2
    PolarStar JACK HPA Conversion Kit V2 Parts
    PolarStar JACK HPA Conversion Kit
    $346.99
    Polarstar F2 V2 for M4/M16
    Polarstar F2 V2 for M4/M16
    Polarstar F2 V2 HPA Conversion Kit for M4/M16
    $441.00
    Polarstar Kythera V2 for M4/M16
    Polarstar Kythera V2 for M4/M16
    Polarstar Kythera SA (Semi Auto) V2 for M4/M16
    $280.00
    PolarStar Airsoft PR-15 V2 Gen3 Fusion Engine Electro-Pneumatic Gearbox Kit
    $520.00