This is a ProMag 30-round magazine for AR-15 rifles in 5.56mm/.223 Rem
Providing the ultimate in flexibility, customizability and reliability, the AR-15 platform is a perfect addition to any shooter’s arsenal. Customize and modify your rifle to your heart’s content—and ProMag magazines are there to keep it all running smooth …
Featuring heat-treated chrome silicon internal springs, these ProMag magazines are designed to maximize durability, performance, and service life. They come with ProMag’s lifetime guarantee, so if you ever have a problem you can just return your magazine and get a new one, no questions asked.