International Firearm Corp is proud to offer this complete 410 ga upper that will fit most MIL-SPEC AR-15 Lowers. When you want a little variety in your collection without paying for a whole new gun, why not swap out uppers on your favorite AR-15 to have a totally new option? Don't worry about impacting your zero on a red dot by swapping it between firearms. This complete upper comes equipped with a Vortex Strikefire II Red/Green dot. Don't worry about tracking down a new magazine either. Included in the package is a 9 round magazine that fits standard AR-15 MIL-SPEC lowers. This upper is built on an 18.5" barrel to offer accuracy without creating a top heavy firearm.