英语翻译The only inner packaging should be the packaging to make

英语翻译The only inner packaging should be the packaging to make each unit a sellable unit,or materials to prevent damage to the contents in the carton.only 我的翻译是：单一的内包装必须是可销售的单元，或用材料以防止在箱内磨损。－－－好像还不太顺：）