The Caldwell Pic Rail Adapter is great 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. Utilizes both shoulder sling and pic rail mounted accessory at the same time Adjust the tension on front/rear with T20 screws Change the vertical angle of the adapter Align with the barrel instead of the stock Constructed of steel and nylon