F2 HPA Conversion Kit V2 / M4

F2 is a dedicated conversion kit designed by Polarstar to fit the V2 gearbox used in the AR-15 / M4 / M16-pattern replicas. It is a direct successor to the previous, well-acclaimed Fusion HPA engine. With advancements in layout, construction, and materials, the F2 offers a compact, efficient, and flexible design. F2 boasts durable construction with a heavy emphasis on CNC-machined components, precise fitting, and tight tolerances. This guarantees high quality and excellent performance of the finished product. The engine incorporates a one-piece poppet valve of a new design that allows it to operate in a wide range of air pressures between 45 and 145psi. The sturdy construction allows the adjustment of the engine power to match the energy requirements anywhere from CQB to DMR-type replicas. The F2 HPA Conversion set offers excellent reliability, a broad power adjustment range, and phenomenal durability in a compact and flexible package, making it a prime choice for all AR-15 pattern replicas.