PolarStar “Kythera” HPA Engine for Airsoft Rifles (Model: SA – Ver3 AK)

PolarStar Kythera SA V3 Mechanical HPA Engine – Precision Redefined for AK Airsoft Rifles

The PolarStar Kythera SA V3 is a revolutionary leap forward in airsoft HPA technology—designed from the ground up as a mechanical, high-performance drop-in engine for Version 3 AK platforms. Built without electronics, FCUs, or batteries, the Kythera sets a new standard for mechanical reliability, consistency, and realism.

This is not a repurposed solenoid system. The Kythera was engineered entirely from scratch to deliver exceptional performance with a robust trigger feel, consistent nozzle movement, and realistic semi-automatic operation. Whether you’re building a rugged DMR or need an efficient CQB platform, the Kythera adapts seamlessly—thanks to its wide pressure range (60–180psi) and easily adjustable velocity output from 270 to 500 FPS.

True Mechanical Innovation

At the heart of the Kythera is a patent-pending valve mechanism that enables the system to complete a full shot cycle entirely on trigger pull. That means each round is chambered and fired in one fluid, uninterrupted motion—without needing to reset the trigger between shots. The result is smooth, reliable cycling and minimal risk of double feeding, even during rapid follow-ups.

Unlike solenoid-based systems, there’s no need for electronics or programming. The Kythera is 100% mechanical, waterproof, and perfect for players who demand reliability without complication.

Realistic, Adjustable Trigger

The Kythera’s standout feature is its incredibly realistic trigger feel. It mimics a real single-action firearm using hardened steel sears and a stainless steel spool valve. The result? A crisp break and audible reset that feels just like a real firearm. You can fully adjust trigger weight, overtravel, and pull length to fine-tune your responsiveness.

Extreme Efficiency and Consistency

Without a pilot valve consuming air, the Kythera fires 100% of the input air through the nozzle. Combined with the balanced valve design, this translates to superior gas efficiency and incredible shot-to-shot consistency—even at lower operating pressures.

Whether you’re dropping rounds at 270 FPS for CQB or hitting 500 FPS for sniper applications, the Kythera delivers reliable velocity and power on demand. Simply dial in your air pressure and go.

Simple Installation, Universal Compatibility

The Kythera SA V3 installs into most standard Version 3 gearboxes (LCT-style AKs) without modification. It’s a self-contained unit that retains key gearbox functions like selector switches, safeties, and trigger assemblies. With no electronics, there’s no need to wire or reconfigure your internals.

A steel charging cord ensures manual cocking in low-pressure emergencies, and can be routed through the grip or attached to the charging handle.

Specifications

• Operating Pressure: 60 – 180psi

• Velocity Range: 270 – 500 FPS (with 0.20g BB & 6.05x380mm barrel)

• Fire Mode: Semi-automatic

• Compatibility: Most V3 gearboxes / LCT AKs

• Material: Aluminum & steel

• Manufacturer: PolarStar Airsoft