Spyder MR100 PRO Semi-Auto Paintball Marker Military Style Paintball Marker Air Efficient EKO Valve System (Patent Pending) shoots up to 1500 shots from a 20 oz CO2 tank- High Impact Polymer Clamping Feedneck-Two Finger Trigger-Matte Anodized Finish-Aluminum Side Picatinny Rail Mounting System High Impact Polymer Vertical Fore-Grip-Aluminum Trigger Frame-Pull Pin Top Cocking Delrin Bolt-Quick Disconnect Pin One Piece Velocity Adjuster/Spring Guide-Anti-Double Feed Ball Detent-Steel Braided Hose-Operates on CO2 or Compressed Air.