Does not fit m&p10 sport - Strike Industries AR308 Enhanced Ultimate Dust Cover

First disappointment is find out this thing is polymer, didnt see that anywhere in the description. I guess the one i had seen in a video which is steel or aluminum is the Gen 2 version. The internal "seal" lip does not fit the contour of the ejection port on an M&P10. i cut away some of the lip with an exacto knife to make it fit, only to realize that the fixed end of the "rod" is also polymer and does not turn nicely in the hole. combined with a weak spring and an overall length that is probably a bit too long for the M&P, the port only opens about 1/3 of the way when you pull the charging handle. Completely useless to me, even with modifications. I could probably cut some of the sides away to make it fit more losely, and maybe smooth up the polymer pin, but not really worth it at this point. too much disappointment. Boo.