Giúp s?n ph?m n?i b?t: V?i các ???ng nét in ?n s?c s?o, màu s?c t??i sáng b?t m?t s? giúp s?n ph?m n?i b?n b?t so v?i ??i th?. T? ?ó giúp b?n d? dàng chi?m tr?n ?u th? c?nh tranh. These pumps are used for pumping down the column. Once the column reaches the expected vacuum stage, the backing or roughing pump is often turned off to lessen m