The Amend2 13 round magazine designed for use in the Glock 23 and is a sturdy, reliable .40 caliber magazine made of advance polymer material. It is a light, durable and excellent alternative to the standard Glock OEM magazine. This magazine has Amend2's unique baseplate to truly make it one of a kind. Features: Sturdy Impact-resistance polymer for increased strength Heavy duty, non-memory and non-corrosive spring Made in USA