PolarStarJACK Conversion Kit

PolarStarJACK Conversion Kit

Ultra-Compact Drop-In Performance. Blistering ROF. Proven PolarStar Reliability.

Upgrade your primary rifle with the legendary speed, air efficiency, and rock-solid reliability of the PolarStar JACK HPA Engine. Designed as an accessible, high-performance electro-pneumatic drop-in conversion, the JACK replaces your AEG gearbox's internal cylinder assembly to deliver instant trigger response and pinpoint FPS consistency.

Utilizing a single-solenoid, centre-line design, the JACK minimizes moving parts to maximize durability and air efficiency. Whether you are running tight CQB arenas or stretching out long-range shots in woodland skirmishes, the JACK provides effortless velocity adjustment and fire-rate customization through the included PolarStar Micro FCU.

Variant Options Available

V2 Platform (M4/M16/AR-15/MP5):

Includes the V2 nozzle, switch board, and wire harness designed for seamless drop-in installation into standard Version 2 AEG gearboxes.

V3 Platform (AK-47/AK-74/G36/AUG):

Includes the V3 nozzle, offset trigger switch board, and specialized V3 wire harness for Version 3 AEG gearboxes.

Key Features

• Ultra-Compact Centre-Line Design: Direct cylinder replacement housing fits into almost any standard AEG gearbox shell with minimal fitting.
• High-Speed Single-Solenoid Performance: Engineered with only one moving part (the nozzle), maximizing air efficiency and reducing potential failure points.
• Full FCU Programmability: The included PolarStar Micro FCU allows instant adjustment of Rate of Fire (1–30+ RPS), Nozzle Dwell, and Burst firing modes on the fly.
• Tool-Less Velocity Tuning: Adjust your muzzle velocity (FPS) instantly by altering your HPA regulator pressure, no spring swaps or teardowns needed.
• Open-Bolt Operating System: Delivers lightning-fast initial trigger response for instant shot placement during high-speed engagements.
• Broad Pressure Range: Operates smoothly across 40 to 130 PSI to easily adapt to strict field energy limits.

Technical Specifications

BZ Tech Team Advice:

• Nozzle Dwell Tuning (dN): Lower your FCU Nozzle Dwell (dN) value until the engine begins to skip BBs or misfeed, then bump it back up 2–3 points. This ensures you aren't wasting tank air on every shot!
• Alignment Matters: Centre-line alignment between the JACK nozzle and your hop-up bucking is key. Ensure your gearbox shell sits square inside your receiver to prevent air leaks or mid-cap feeding jams.
• Battery Maintenance: Always unplug your 7.4v JST FCU battery when packing away your kit, the Micro FCU draws a tiny standby current that can drain LiPo batteries completely over time.