Extreme Precision Bipod with 13" to 23" Adjustable Spring for Tactical Airsoft Air Rifle Gun Hunting Shooting Fits all Standard 20 mm Picatinny Rail. Quickly Attach to or Detach From the Rail Mount Using Existing Quick Release Screw. Quick Release Button for Multi Level Locking Positions Legs with 12mm Increment. Legs can be Folded Forward or Backword. Made of Durable, High Density Aluminum.