PolarStar Universal Gas Stock (UGS) CO2 Insert – Type 33g
High-Pressure Performance in a Compact Package

The PolarStar Universal Gas Stock (UGS) CO2 Insert – 33g Type is a precision-engineered solution built for serious airsoft players who demand consistency, reliability, and efficiency from their HPA systems. Designed and manufactured by PolarStar, a leader in high-performance airsoft technology, this CO2 insert allows users to power their UGS or CGS stocks, as well as most HPA regulators and air rigs that can accept up to 900 PSI. Whether you’re running an F2, Fusion Engine, or JACK, the UGS CO2 Insert is built to deliver the steady pressure and smooth performance you need on the field.

Precision Engineering for Performance

At its core, this CO2 insert is designed for precision airflow and reliability. Each unit is equipped with an expansion chamber, anti-siphon system, 5-micron filter, and check valve, ensuring smooth gas delivery with no risk of liquid CO2 entering the system. This means you’ll experience consistent FPS readings and reduced cooldown effects even during extended use — a must-have advantage for competitive players or those using their setup in varying temperatures and conditions.

Universal Compatibility

The PolarStar UGS CO2 Insert is built to integrate seamlessly with a wide range of setups. It’s compatible with both UGS and CGS stocks and will also fit most standard HPA regulators or air rigs that can safely handle 900 PSI. Featuring standard ASA threading, installation is straightforward and secure, allowing for quick attachment to your air rig or stock system.

⚠️ Note: To use this insert with the UGS, a Milspec rail (sold separately) must be added before installation.

Optimized for Longevity and Efficiency

PolarStar designed this insert with efficiency in mind. When paired with an F2 engine running at 1.5 joules with .28g BBs and a 6.05x380mm barrel, you can expect impressive results:

• 12g CO2 cartridge: ~180 shots

• 33g CO2 cartridge: ~500 shots

That’s nearly triple the capacity, giving you longer playtime between cartridge changes without sacrificing consistency or shot performance. The 33g model uses threaded CO2 cartridges for a secure, airtight seal, while 12g models use standard CO2 capsules commonly found in airsoft and air guns.

Built for Safety and Stability

PolarStar is known for their commitment to safety and durability, and this insert is no exception. Every detail—from the reinforced metal body to the precision-engineered internals—is built to handle the stresses of high-pressure CO2 operation safely. The integrated check valve ensures proper venting and prevents backflow, while the anti-siphon system ensures only gas (not liquid) CO2 enters your regulator.

⚠️ Important: The insert cannot be pressurized before installation into the stock or regulator. Always follow manufacturer guidelines for safe handling and installation.

Why Choose PolarStar UGS CO2 Inserts?

• Trusted Brand: PolarStar has long been the benchmark for high-end airsoft HPA technology.

• Exceptional Build Quality: Made from top-grade materials for durability and performance.

• Consistent Output: Stable pressure ensures reliable shot-to-shot performance.

• Versatility: Works across a wide range of airsoft HPA setups.

• Efficiency: Higher shot count per cartridge saves time and money during gameplay.

Specifications

• Type: 33g CO2 Insert

• Compatibility: UGS, CGS, and most HPA regulators/air rigs (up to 900 PSI)

• Threading: Standard ASA

• Components: Expansion chamber, anti-siphon system, 5-micron filter, check valve

• Shot Count: ~500 shots (using F2 at 1.5J / .28g BBs)

• Manufacturer: PolarStar

Conclusion

For players seeking maximum reliability, performance, and efficiency, the PolarStar UGS 33g CO2 Insert is the gold standard. Whether you’re running a precision DMR or a high-speed CQB rifle, this insert delivers consistent gas output and high shot counts in a compact, rugged design. Backed by PolarStar’s legendary engineering, it’s the ideal upgrade for any serious airsoft enthusiast.