MAGPUL PMAG 20LR Gen 3 magazines are designed for SR25 magazine pattern rifles chambered in 7.62 NATO/.308 Winchester or 6.5 Creedmoor. These magazines have quickly become the industry standard due to their extreme durability, reliability, and cost effectiveness. The Gen 3 magazines feature the new constant curve geometric body, anti-tilt follower and other minor improvements. The polymer magazine reduces overall magazine weight by half without sacrificing durability. MAGPUL PMAG LR/SR series magazines are a must-have if you own a compatible SR25 magazine pattern rifle.