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..."