Condenser aperture-A little laser-bored hole in the flat strip of molybdenum positioned near the condenser lens that assists to limit 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 Hello?n thanh toánThe second anode (Anode two) accelerates the electrons to the require