Combined trigger board and FCU makes for Spartan's most robust HPA system yet Tuning your gun takes less than a minute due to the unique Live-Fire Tuning Simple, straightforward design allows users to have precise control over several different performance adjustments Use the FCU to adjust your dwell timing, rate of fire, and burst settings on your HPA systemSpecifications: Brand Wolverine AIrsoft Compatibility Compatible with Wolverine Spartan Engine 1X FCU