Version 2.1 of the hop-up alignment system, designed for M4 AEG HPA replicas using:
- PolarStar F1™ HPA Conversion Kit (universal drop-in for V2 gearboxes, programmable pneumatic system with dual-stage firing and high efficiency).
- Silent Industries ALPHA M4/16 AEG/HPA Chamber (CNC hop-up chamber with TRUE-TDC, tension ring system, and full bucking lip support, designed as a “game changer” for HPA builds).
This version of ALPHA is from before 2026; the body is rounded.
This kit ensures solid and precise alignment between the F1 nozzle and the ALPHA chamber, reducing typical HPA issues such as double feeding, mid-cap syndrome, and BB position inconsistency.
The result is more stable feeding and improved shot consistency, fully taking advantage of the direct airflow and fast response of the F1.
Compatibility
| Component | Compatibility |
|---|---|
| HPA Engine | PolarStar F1 M4 HPA Conversion Kit |
| Hop-up Chamber | Silent Industries ALPHA M4/16 AEG/HPA |
| Base Replica | M4 AEG |
| Gearbox | V2 / ICS SPLIT |
What the kit includes
- Rear clip for mounting via rear pin or fixed stock.
- Base with housing for M3 inserts (brass optional).
- Side clip for routing the HPA tube/line.
- Top cap for front locking of the ALPHA chamber, designed to respect the CNC body and barrel adjustment.
- Rear plate with mounting point for an M5 screw (additional reinforcement).
Required components (not included)
- 4× M3 inserts × 4.2 mm
- 4× M3 × 8 SHCS screws
(Recommended purchase links are available in the generic hardware section of the store.)
Recommended products
The most recent models added to the collection



