This is a Kriss Gen 2 MagEx .45 ACP Vector 30-round magazine. Fully assembled using a factory Glock® 21 magazine and Kriss MagEx extension, these 30-round magazines come ready-to-use with compatible firearms including the Kriss Vector, .45 ACP Glock pistols, and other compatible carbines. Featuring the same polymer construction, numbered witness holes and steel reinforcing inserts as factory Glock magazines, these magazines add an extended sleeve that fits 17 additional rounds and sits flush against the magazine well of the Kriss Vector.