The Seneca DoubleShot Double Barrel PCP Air Shotgun is a Precharged pneumatic air shotgun with two smooth bore barrels and on-board pressure gauges.FeaturesBore Diameter: 12.47mm Barrel Thread: 16.6x18 Choke Measurement: 12.4mm The choke reduces the inner barrel diameter from .494" to .486"Patent Pending Air Distributor allows a follow-up shot in less than 2 secondsOptional 11mm dovetail scope rail for optics can be added (not included) Ambidextrous hardwood stockRubber ButtpadVelocity up to 1130 fps with shotshellsVelocity up to 425 fps with Air Bolts (170+ FPE)Velocity up to 600 fps with Round Balls (140+ FPE)Thread on chokes (Easily removed for use with Air Bolt or Slugs)Front bead sight (no rear sight)244 cc air cylinder