You'll find leading brands such as POLARSTAR, Wolverine Airsoft, GATE (Pulsar), Balystik, NINJA, HK Army, Armotech, OXYGEN, Amped, Z-Parts, Creeper Concept, BO-Manufacture, Tapp Airsoft, DYE and Mancraft.
There are several different types of HPA system. There are electro-pneumatic systems operating with FCUs (powered by small special HPA batteries), offering the possibility of modifying several parameters such as rate of fire, air volume and nozzle delay times. You'll find these functions on Polarstar's F1 / F2 / Fusion Engine and Wolverine systems. The Wolverine systems can be installed directly inside or in place of the gearbox of your AEG airsoft replica.
You can also easily convert a GBBR airsoft replica into an HPA replica. In this case, simply replace the original valves on your magazines with drilled or undrilled valves. Non-drilled valves screw directly into the threads of the original filler valve. Drilled valves, on the other hand, are screwed into the structure of the magazine to provide an outlet when your original valve doesn't allow it, depending on its location (blocked by the replica's loading magwell, for example). For the rest, a standard connection will suffice, i.e. the addition of a cylinder, an HPA line and a regulator.
Finally, you'll find mechanical HPA systems, like the KYTHERA Polarstar or Reaper M Wolverine. Like the classic models, they replace a large part of your gearbox. As the system is entirely mechanical, no battery is required. You'll get realistic, satisfying trigger pressure sensations.
