GB means GUO BIAO(China National Standard), which is simliar as JIS(Japanese Industrial Standards),DIN(Deutsches Institut für Normung e.V. in English, the German Institute for Standardization).Sometimes Chinese use CB Standard (CHUAN BO-ships) to regulate material ship building industry,etc. So we just show you their photos for reference. If you need it in USA, Canada, Brazil, or Chile,etc, just contact Ekaship Hardware Ltd.
