Ruger 90711 Ruger-5.7 Value Pack 20rd 5.7x28mm Black Oxide Steel 2 Per Pack
https://www.tandktactical.com/shop/736676907113-ruger-90711-ruger-5-7-value-pack-20rd-5-7x28mm-black-oxide-steel-2-per-pack-21613
https://www.tandktactical.com/web/image/product.template/21613/image_1920?unique=733a435
This value pack replacement or spare magazine is compatible with your Ruger 57. Made in the USA.
