The Sadlak QD Post replaces the stock M1A/M14 front swivel for a more rugged, durable bi-pod attachment. It eliminates cracking of the stock during heavy recoil or rough use. The internal oval nut plate and external oval washer has approximately 3 times the load disbursement over the standard single Quick Disconnect (QD) post. Designed for use with a Harris bi-pod or other bi-pods using the standard QD post. Once the QD post is installed, you have flexibility of attaching a bi-pod or detachable Sling Swivel. All hardware and screws have manganese phosphate finish. The internal nut plate can be further secured by using a Devcon steel epoxy or other bedding compound. Notes: Choose your Front Rail based upon your stock style, i.e. Universal, Wood, Fiberglass, Synthetic or Supermatch.FOR NATIONAL MATCH STOCK CHOOSE SUPERMATCH.