American Tactical Imports, or ATI, brings an advanced German high-capacity Schmeisser GmbH magazine to us here in the US. This 60 round AR-15 magazine uses a very durable and lightweight glass-reinforced polymer body, and a unique double-spring system internally, to provide shooters with 60 rounds of uninterrupted fire. Tested for reliable feeding from full-auto and suppressed weapons, this magazine can feed rounds consistently as fast as you can squeeze the trigger. Disassembly is not difficult and allows the user to clean and maintain their magazine easily, but be aware that the spring tension is significant. 
Generation 2 - Featuring last round bolt hold-open and Window for accurate round availability.
Specifications:
Capacity: 60 Rounds
Caliber: 5.56x45 NATO / .223 Remington
Compatability: FN SCAR MK 16/16S, SA-80, HK416, M27
Material: polyamide fiberglass polymer
Disclaimer:
The Schmeisser S60 was built specifically for .223REM or 5.56X45MM ammo only.  Schmeisser & American Tactical have done some testing and found that the S60 may not operate with all types of .300 Blackout ammo.  Due to inconsistencies with different brands, Schmeisser does not recommend using 300 Blackout with this magazine.  Failure for the magazine to operate with 300 Blackout is not covered by American Tactical's Limited Lifetime Warranty.
The Schmeisser S60 has a very powerful high tension spring.  Please use caution if disassembling the magazine for maintenence.  If not properly secured, spring may eject from magazine when floor plate is removed and can cause serious injury.
 
Limited Lifetime Warranty and Product Return Policy Please Click Link For Further Details: 
http://www.americantactical.us/warranty.html