PolarStar Airsoft's answer to Wolverine Airsoft's SMP, the F1 Drop-in HPA Engine is now in production. Whilst similar to the SMP it uses a separate nozzle and poppet and can be dropped to any AEG gearbox as there is the centerline and offset versions...

"Yes, that's right! The long awaited F1's are finally in production and are slated to be released in March.

F1 Center-line: $350.00
F1 Offset: $375.00

F1 will be slightly more air efficient than Jack..."

UPDATE: More indepth information added...

The F1 is a high performance, universal HPA (High Pressure Air) drop-in cylinder designed to fit virtually any AEG gearbox. It is available as both a Centerline version, which will work with most common gearbox types, but it is also available in an Offset version to work with those unique gearboxes such the V6 and V7. It replaces the original gearbox components with a programmable pneumatic system allowing for higher performance, greater reliability and complete adjustability. This allows the F1 to fill any role ranging from CQB to sniper with no additional components needed.

A lot of you are going to wonder what the differences are between the F1 and JACK. The main difference is that the JACK is only designed to work with the more common models of AEG's which all use centerline nozzles. The F1 is able to work with the more unique models that use an offset nozzle as well as the common centerline models so it has greater compatibility. There is also a difference in how the two system work internally. The JACK uses a small solenoid for nozzle movement only. The position of the nozzle within JACK is what allows or prevents air from flowing down the nozzle since the nozzle itself acts as the poppet valve.

The F1 uses a custom solenoid designed by PolarStar and manufactured by MAC Valves. The design allows the solenoid to become an integral part of the system and not simply a switch to control gas flow. This not only makes the F1 more compact but also minimizes the dead volume inside of the system, increasing air efficiency and decreasing response time.

Like JACK, the solenoid in F1 also controls nozzle movement and the nozzle position also controls firing air, but only for one of the two firing stages. In the two-stage system the nozzle travels a certain distance, then begins to allow airflow through the bore. After traveling completely forward, a secondary firing port opens to allow increased flow though the nozzle.

Unlike similar systems, the F1 incorporates a dual purpose flow control system which allows for nozzle speed regulation and two stage firing through an integral check valve. The check valve system regulates nozzle speed based on the direction of movement while also controlling flow to the secondary firing point. The flow control limits the forward speed of the nozzle based on a specific orifice size, but allows the nozzle to retract without restriction. This is similar to an AEG piston o-ring, depending on the direction of nozzle movement (or nozzle position) the check valve seal is expanded out of, or compressed into a groove, sealing off ports. This unique design promotes both enhanced feeding and smoother chambering.

Despite its sophisticated design, the F1 only has 5 parts which translates into extreme reliability and makes maintaining the F1 very easy. To further simplify maintenance, the F1 requires no tools for disassembly.