The CaldwellA(R) Pic Rail Adapter is perfect for utilizing both your shoulder sling and a pic rail mounted accessory at the same time. By adjusting the tension on the front and rear T20 screws you can change the vertical angle of the Pic Rail Adapter to align with the barrel instead of the stock. A curved "fore-end style" profile ensures a perfect mating surface for the bipod. Features Ability to align the adapter with the barrel instead of the stock