firm offer

详细解释:【经】 确定的报(发)价确盘, 稳价, 限期内有效发价

例句：

If you can supply goods of the type and quality we require, please make us a firm offer and quote your lowest price.如贵方能提供我们所需型号和质量的货物，请向我们报实盘并报你方最低价格。