This is the Magpul PMAG GEN M3 AR-10 .308/7.62×51 20-round window magazine. 

You’ve been asking, and Magpul listened! The PMAG GEN M3 window magazines are now available to feed your favorite AR-10 rifles!

Inside the impact and crush-resistant polymer body, you’ll find a corrosion-resistant stainless steel spring that together delivers one of the most durable polymer magazines on the market. Keeping the magazines feeding flawlessly is an anti-tilt, self-lubricating follower that lets you rest easy, knowing your rounds will be ready whenever you are. 

With a paint pen dot matrix for easy magazine identification and anti-glare witness windows for instant capacity checks, Magpul left nothing to be desired. Whether you use your AR-10 for home defense, competitions, or plain old fun at the range, these magazines are the ones you’ll want feeding it! 

These will move fast, so add some to your cart before you check out!