The Strike Industries Overmolded Ultimate Dust Cover Ejection Port Cover AR-15 for .223/5.56 is the next iteration of their Ultimate Dust Covers (UDC). The SI patent pending "True Seal" with double injection mold and overmolded rubberized soft sealing lip provides a better seal to prevent debris and water from entering when the cover is closed. The AR Overmolded UDC comes pre-assembled with all the parts needed for a quick tool-less installation and easy disassembly if using a common tool such as a pen. Built into the UDC is an adjustable detent set screw to compensate for wear on the upper receiver. The SI patent pending noise-reduction rubber padding also makes it nearly 100% silent during activation. Made of overmolded, high-strength impact, blended SI Polmer Extreme material, the SI AR Overmolded UDC does not deform or get bent out of shape. Consider the Strike Industries Overmolded Ultimate Dust Cover Ejection Port Cover for .223/5.56 on a new build or when you are going to untorque the barrel nut as this is adjustable in just 5 to 10 seconds.