GTEK M170R FEATURES:Gamma Core DrivetrainSpool Valve OperationQuick-Release Bolt MechanismHoseless Air Transfer System135PSI Operating PressureST1 Bolt3-Point Adjustable Pivot TriggerTwin Micro Ball-Raced Trigger PivotToolless Detent Access6061-T6 Aluminium ConstructionSL6 Inline RegulatorShaft 4/5 Compatible 14.5" Two-Piece BarrelPOPS ASALow-Rise FeedneckBattery Free Playing Experience