backstrap meaning in English

背部腰带
后带
脊框
手枪枪身后部

For the shoes with elastic on the backstrap , please try not to use upper material to cover the elastic , see if u can use the matching color elastic to make the backstrap , let me know because too many complaint and return from the customer today
那些背带部分有橡皮筋的鞋子,请试试不用东西包住橡皮筋,看看你能不能用颜色相配的橡皮筋去做背带,如果可以的话,让我知道，因为我们最近有太多来自客户的投诉和退货了