PolarStar Kythera SA™ Drop-In Conversion Kit

The Kythera SA™ is PolarStar's most eagerly anticipated product in over a decade — and a radical departure from everything that came before it. The Kythera uses no battery, no FCU, and no electronics whatsoever. It is completely mechanical, completely waterproof, and completely unlike anything else on the market. PolarStar Filter Fitting included.

Named after the Antikythera Mechanism — a 2nd-century B.C. astronomical computer so advanced that scientists studied it for decades to understand its purpose — the Kythera valve mechanism is similarly intelligent: few parts, easy to maintain, yet incorporating design principles found nowhere else in airsoft.

What Makes It Unique

• Realistic Trigger: Hardened alloy steel sears catch and release a stainless steel spool valve exactly as a real single-action firearm trigger operates. Distinct break, distinct reset. Adjustable for weight, length of pull, and over travel.
• Complete Shot Cycle on Pull: Delivers proven closed bolt performance mechanically. No trigger release required before the next round chambers. Ready to fire again before the trigger fully resets.
• Maximum Efficiency: No pilot valve — 100% of air goes through the nozzle. Consistent valve release every shot regardless of trigger input.
• Universal Charging Cord: Steel cocking cord routes through the grip or attaches to the charging handle for field access if the system stalls (typically only if run completely out of air).
• Easy Installation: Installs as a single assembly into a standard gearbox. No gearbox modification typically required.

Gel Ball Compatible

Kythera SA kits can be configured for gel ball use (7–8mm projectiles). Contact us for details.

Performance

• Velocity: 270–500fps w/ .20g (6.05×380mm barrel) across 60–180psi operating range
• ROF: 30rps in most standard configurations
• Operating Pressure Range: 60–180psi — one system covers CQB to DMR by adjusting input pressure
• Adjustable: Nozzle dwell, return speed, trigger weight, length of pull, over travel