PolarStar F2 AK / V3 HPA Conversion Kit | HPA Drop In Kit
PolarStar F2 AK / V3 HPA Conversion Kit | HPA Drop In Kit

The PolarStar F2 V3 Conversion kit for V3 AK rifles allows you to transform your existing AEG into a high performance HPA powered rifle. The F2V3 Conversion kit comes with an F2V3 Switchboard #2 nozzle which supports most AK models from G&G, Tokyo Marui, CYMA, and other clones.  

What Is F2?

F2 is essentially a Mini Fusion Engine. It offers the same adjust-ability and performance as the Fusion Engine in a cylinder sized package.

Patented Dual Solenoid Design

The dual solenoid design of the F2™ provides the same functionality as the legendary Fusion Engine™ but in a more compact, efficient and flexible design. Dual solenoids allow for the nozzle and the poppet valve to be adjusted independently of each other for unparalleled control over both the loading time and air volume used. Additionally, this makes it possible to change the firing sequence giving it the ability to operate in both true closed bolt as well as "AEG" mode.

Increased Efficiency

The F2™ incorporates a new one-piece, lightweight poppet valve design yet still operates on the same principle as the Fusion Engine™ poppet. This valve is able to operate at lower pressures and uses less air volume to function which optimizes air efficiency.

The standard F2 poppet is equivilent to the Red Low-Flow poppet of the Fusion Engine.

The robust design of the F2™ allows for an operating pressure range of 45psi to 145psi which enables it to achieve velocities from CQB to DMR while employing only one nozzle for the entire velocity adjustment range. 

Spring Loaded Nozzle

The F2™ nozzle is spring biased forward which provides a consistent loading force regardless of operating pressure. It shares the same spring as the Fusion Engine™ with both light and heavy spring options available to adjust the loading force. 

Complete Tuning Control

The F2™ comes complete with a Fire Control Unit (FCU) that has an LCD display that allows you to tune your F2 to your liking! Adjust it's dwell, rate of fire, burst modes, nozzle feeding, and more!


Velocity Range: 250fps - 500fps

Operating Presure: 45-145 PSI

Compatibility: ALL AEG

Offset and Centerline cylinders and nozzles.

Wire harnesses are available in 7.5", 13" and 18" standard lengths

Interchangeable Bushing Inserts which prevent any movement of F2 within the gearbox.

Custom nozzle lengths available.

Low velocity poppets (< 1J) available.

Light and Heavy nozzle springs available.

What is the difference between F2, F1 and JACK?

Both F1 and JACK are "open bolt" systems, meaning the nozzle is in the rearward position when the system is idle and the round is fired during the forward movement of the nozzle. F2 is a dual-solenoid system which allows for complete control over the shot cycle.

What is the warranty for F2?

F2 systems are covered by a 1 year warranty against defects in material or manufacturing.

Compatability and Nozzles

Over 20 standard F2 nozzles are available for installation into a wide range of replicas. These are numbered, rather than named, since a single nozzle is often compatible with multiple replicas. The "Original Model" listed in the table is the replica from which the nozzle measurements were taken and is for reference.

If your gun is not listed in our Compatiblity Database a recommended nozzle length may calculated by measuring your original gearbox and applying the following formula: TIP = F + B - (A/2) - .057. A more precise measurement (which accounts for the hopup and bucking in use) may be obtained by installing a nozzle into the system which is slightly too long for the replica and measuring the nozzle setback when placed into the hopup.

If you do not see a Standard Nozzle listed within +/- .010" of the calculated measurement please contact us with your gearbox measurements and we can have PolarStar cut a custom nozzle for you.

PolarStar F2 AK / V3 HPA Conversion Kit | HPA Drop In Kit