Spyder Xtra Semi-Auto Paintball Marker Air Efficient EKO Valve System (Patent Pending) shoots up to 1500 shots from a 20 oz CO2 tank Aluminum Clamping Feedneck-Hard Anodized Matte Finish-Standard CA Thread Vertical Adapter-Aluminum Foregrip Pull Pin Top Cocking Delrin Bolt-Tool-Free Striker Plug Design-10" Micro Ported Barrel-All Aluminum Construction-Ergonomically Designed Aluminum Trigger Frame No-Slip Rubber Grip Panel-Two Finger Trigger-External Velocity Adjuster-Steel Braided Hose Line Inline Bottom-line ASA-Operates on CO2 or Compressed Air.