Rock Island 54171 1911 13rd 45 ACP Blued Metal (High Capacity)
http://www.tandktactical.com/shop/4806015541714-rock-island-54171-1911-13rd-45-acp-blued-metal-high-capacity-5147
http://www.tandktactical.com/web/image/product.template/5147/image_1920?unique=2a7b81d
This replacement or spare magazine is compatible with your Rock Island 1911.