It's not ready critical half baked problem that require revision - Magpul Industries Enhanced Ejection Port Cover

This has alot of potential to be a cheap weight saver at 9 grams on my scale about as much as spending 60-70$ for a vseven air dust cover with vseven enlarged type 2 rod. As of right now it's only purpose is the bin of shame full of discontinued memorabilia, tried in a colt cage code stripped 6920 upper, 6940 upper, Colt m5 cqc upper, Super duty upper reciever. All have an identical problem following the directions to the letter, you will not have enough spring tension, when the carrier is moved back to extract, the dust cover will open part way but hit a "wall" to swinging never beyond the one o clock position. The cover needs at least 2 more coils of tension on the spring to fight the difference. It's not a reciever issue this is a legitimate design oversight. Installing this on any upper you will get stovepipes as the round will not over come the difference to flip out the rest of the way, stick with a gi or vseven dust cover.