KNS Precision AR15/M16 .250 Diameter Push Button Pivot Pin w/QD Swivels Adapter Black. When pushed the stainless steel keeper pins retract for easy pin removal. Once the pin is in place simply push the button and slide the stud over the retracting balls and release. Put your sling swivel into the stud and you are ready to place your sling on the rifle. This eliminates any weight on the barrel of the weapon. When sling swivel is inserted in the stud the stud is locked onto the pin. You must remove the sling swivel from the stud in order to remove the stud from the pin. Specifications for KNS Precision AR15/M16 .250 Diameter Push Button Pivot Pin: Manufacturer: KNS Precision Finish: Black Trigger Pin Size: 0.25 Color: Black Country of Origin: USA Package Contents: KNS Precision AR15/M16 .250 Diameter Push Button Pivot Pin KNS Precision PBPIVOT250-QD: AR15/M16 .250 Diameter Push Button Pivot Pin w/QD Swivels Adapter Black