MGI's D-Fender "D-Ring" assist in eliminating extraction problems and increases the reliability and performance in the M16/M4/AR-15 family of weapons. This High-Tech, composite "D-Ring" increases extractor spring force by 4x and has been tested and approved by the United States Department of the Army. It is also in use with British SAS, US Navy Special Ops, the Canadian Military, and multiple law enforcement agencies nation wide. MGI D-Rings have also logged over 1 Million rounds on individual D-Rings proving just how tough they really are.
According to the US Department of the Army, "D rings have been used on three configurations of the M16 type weapons and have always been found to aide in reliability." Increase the reliability of your AR with the addition of a MGI D-Ring.
For more on this part, go to https://www.mgi-military.com/store/index.php?product_id=5&type=&category=7
For more on MGI, go to http://www.mgi-military.com/index.php?id=1