· Reinforced piston designed to match exact tolerances and measurements of Krytac internal components and builds on previous Prometheus designs · Included: Krytac Hard Piston x 1 · Compatibility (Krytac standard M4 AEG): - Trident series- LVOA series - GPR-CC- Barrett REC7 https://www.youtube.com/embed/1-AuR67VlnE