HPA Kythera SA Conversion Kit for A&K/JG SR25

The Kythera has been the most eagerly anticipated products from PolarStar in the past decade. This HPA system is a radical departure from all previous systems that PolarStar has produced since the Kythera does not use a battery, an FCU or any type of electronics. The Kythera is completely mechanical. This means you never have to worry about charging batteries or work with delicate electronics. It also means that the system is completely waterproof.

The name "Kythera" (ky-the-ra) was derived from the Antikythera Mechanism which is a mysterious device that was discovered by sponge divers off the coast of the Greek island Antikyther. The mechanism was so advanced in design that scientists have been studying it for decades to discover its purpose. The machine dates from around the end of the 2nd century B.C. and is the most sophisticated mechanism known from the ancient world. Nothing as complex is known for the next thousand years. The Antikythera Mechanism is now understood to be dedicated to astronomical phenomena and operates as a complex mechanical "computer" which tracks the cycles of the Solar System.

For this reason we used the name Kythera for the valve mechanism at the core of a new line of PolarStar mechanical HPA systems. Although it contains very few parts and is easy to install and maintain, the system incorporates a very intelligent design and is unlike anything else on the market. The system was designed as a mechanical system from the ground up and uses a realistic trigger mechanism which can be applied to single-shot, semi-automatic and fully-automatic systems.

The first of these systems is Kythera SA (Semi-Automatic), the semi-auto-only variant for use in AEG gearboxes.

So, what makes the Kythera so unique?

Realistic Trigger

What sets this system apart from other mechanical systems is the design of its trigger. The trigger mechanism is designed to replicate the function, weight and feel of a real single-action firearm..