PolarStar Direct Attach Front Cylinder

The Alignment Revolution is a Monolithic Assembly

If you've ever spent hours shimming a gearbox shell just to have your nozzle tilt .5mm and ruin your grouping, you know the pain. We got tired of "good enough" alignment. So we made this.

The PolarStar Direct Attachment is a replacement for the original front cylinder on your F2™ or JACK™. It connects directly to The PolarStar Hop Up Thing, allowing the engine to mount directly to the hop-up itself. Because alignment is now built into the Direct Attachment front cylinders, the upper gearbox shell is no longer needed for alignment. Electronics, trigger, and selector systems can still be housed in a modified shell, printed lower, or completely custom chassis.

How It Works

A two-piece system: the Direct Attach Front Cylinder and an internal Adapter. Thread the PolarStar Hop Up directly into this assembly and the HPA engine, hop-up, and inner barrel become one single, rigid, monolithic unit.

• Zero Nozzle Deflection — Locking everything together eliminates nozzle wiggle or lean during BB loading.
• Consistency = Groups — If the BB loads the same way every time, hop-up effect stays consistent. Consistent hop means tighter groupings.
• Perfect Alignment — Physically impossible for the nozzle to be misaligned with the bore.

What Gearbox Does This Fit?

Short answer: it doesn't exactly need one. Whether you're dropping this into a standard shell to fix a lemon, running Monk Customs Oracle shells, or building a scratch-made chassis from a 3D printer — this system is limited only by your imagination.

Note: The Direct Attachment Front Cylinder and Adapter are sold as shown. The F2™ engine, hop-up, and shell shown in product images are not included and sold separately. Ships from Newark, DE.