What is the F2 from Polarstar? Well, it is a system similar to the Fusion Engine but in the Mini version, the big difference is that everything is done to be housed in the location of the cylinder of your Gearbox.

And its performance is the same as for the Fusion Engine.

As in the Fusion Engine system, the nozzle moves back thanks to the compressed air and it is pushed forward via a return spring which guarantees optimal and regular operation.

You can change its nozzle to adapt it with other types of replicas like the SR25, M240, M249, G36, ARX, Tavor, etc …

Due to its design the F2 can operate from 45psi to 145 psi which makes it possible to play just as well for the CQB as for the counter-sniper in DMR mode.

In addition, its nozzle is biased by a forward spring which provides a consistent load force regardless of the operating pressure.

It shares the same spring as the Fusion Engine™ with light and strong spring options available to adjust the loading force.

Polarstar test:


FPS: 480fps with 0.20g bb with 145 psi pressure

The F2 ™ allows easy speed adjustment by simply changing the inlet pressure and does not require a different nozzle to reach its full speed range.

Using a standard M4 as in the example, the speed can be adjusted from less than 280fps and up to around 480fps with a BB of 0.20 g.

The speed may vary depending on the model, as longer inner barrels will increase the FPS while shorter inner barrels will decrease it.

Rate of fire :

ROF: 30 rounds per second.

The maximum cyclic speed of the F2 ™ is affected by several factors such as the operating pressure as well as the quality of the magazine and the BBs used.

However, 30 bbs per second are achievable in most standard configurations.

Air efficiency:

More than 1000 shots made at 1.5 J with 0.28 g bb

The standard Poppet valve F2™ is equivalent to the low flow red Poppet of the Fusion Engine™.

However, this valve responds faster and requires less air volume to operate, so the F2™ is able to achieve greater air efficiency than even a finely tuned Fusion Engine™.

(Test configuration: Red Poppet / 6.05x375mm inner barrel)

Contents of the box:

  • F2 HPA air system
  • Nozzle Red
  • FCU electronic card (compatible with Fusion Engine, F1 and Jack)
  • Electric cable
  • Switchboard V2