CZ-USA 11385 Bren 2 30rd 7.62x39mm Black Polymer
https://www.tandktactical.com/shop/806703113852-cz-usa-11385-bren-2-30rd-7-62x39mm-black-polymer-16859
https://www.tandktactical.com/web/image/product.template/16859/image_1920?unique=84553e8
Compatible with CZ Bren 2. It features a window round counting.
