Polarstar Jack HPA Engine


Sale price$349.99



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  • SHIPS SAME DAY
  • 14 DAY RETURNS
The Polarstar JACK replaces the original gearbox components with a programmable pneumatic system allowing for higher performance and greater reliability over a gear driven system.  This unit comes with everything you need, from the wire harness, to the triggerboard, to the FCU.  The JACK is a very affordable option, while still retaining the same performance and quality you have come to expect from other PolarStar products. The JACK™ has only one moving part, the nozzle, which acts as its own poppet valve.
  • Designed, manufactured and built in the U.S.A.
  • Assembled from CNC machined aluminum components with high performance Delrin nozzle
  • Universal cylinder design is compatible with numerous gearbox versions

Common Product Questions

Find quick answers about our airsoft products, shipping and policies.

Will this part fit my platform?

Compatibility is product-specific. Check the brand, model, size, and platform named in the product description, such as Tokyo Marui Hi-Capa 4.3 or 5.1, AAP-01, Umarex/VFC Glock, or a particular AEG gearbox type.

Similar-looking parts are not always interchangeable, so contact our team with your exact model if you are unsure.

Do I need tools or gunsmithing?

That depends on the upgrade. Simple external parts may be straightforward, but internal upgrades can require disassembly, reassembly, adjustment and testing.

If you are not comfortable working inside your airsoft gun, our team offers professional tech and custom-build services.

Can LA Airsoft install this part for me?

Yes. We can build and upgrade Hi-Capas, AAP platforms, and rifles. Choose your base gun and parts, then add the appropriate tech service.

The current custom-build service states that builds are normally completed in approximately 3 to 5 days, with the team reviewing the selected parts for compatibility.

How should I maintain this product?

Regular maintenance helps preserve performance and reliability. Keep the product clean, follow the manufacturer’s lubrication instructions, and properly manage batteries, gas systems, and internal components. More advanced repairs or internal servicing should be handled by an experienced airsoft technician.

How quickly will my order ship?

Orders without preorder items are typically packed the same day when placed before 4:30 p.m. Central Time. Please note that occasional delays can occur during especially busy periods or when staffing is limited.

Will this part increase my FPS?

Not every upgrade increases FPS. Some parts are designed primarily for reliability, cycling speed, weight reduction, or gas efficiency. When a product has a tested FPS claim, it should be stated in the listing.