Condenser aperture-A small laser-bored hole in a very flat strip of molybdenum placed near the condenser lens that helps to Restrict spherical aberration.THÊM VÀO GI? NH?N TIN ZALO Gi? hàng c?a b?n có s?n ph?m T?ng ti?n thanh toán: Ti?p t?c mua hàng Th?c hi?n thanh toánA vacuum method is made use of to maintain the expected vacuum stages t