“O” Ring upgrade for Colt M4/M16 .22 and HK 416 .22 and HK MP5 A5 .22
Also fits most Umarex flash hiders that screw onto the 8mm thread
Note: This is an exact match U.S. made “O” Ring
Pro Tip: Replace every 20 disassembles or every two years
MATERIAL – Nitrile, also known as Buna-N rubber or NBR, is a copolymer of Butadiene and Acrylonitrile. It is the most commonly used elastomer for sealing products.
NOTE: This is for a SINGLE “O” ring
If you need more, change the quantity