Allen Boulder BakTrak Sling Black/Yellow. The face of the sling has a panel made from flexible material that helps to keep the sling from twisting while on your shoulder. Quickly adjust this sling with one hand and feel confident carrying your firearm with its 1.25-inch heavy duty webbing and a thumb loop. Swivels are tested to 300 pounds. Specifications for Allen Boulder BakTrak Sling: Manufacturer: Allen Color: Black Features of Allen Baktrak Boulder Rifle Sling BakTrak is a Tacky Backing on the Sling Made from Rubber Gripping Dots One Hand Quick Adjusting 1.25-Inch Heavy Duty Webbing and a Thumb Loop Swivels are Tested to 300 Pounds Package Contents: Allen Baktrak Boulder Rifle Sling Allen 8355: Boulder BakTrak Sling Black/Yellow