Each column blank kit includes a precision-bore polished 316 stainless steel column blank, two zero dead volume external reducing unions (internal unions with 10 mm I.D. blanks) with nuts and ferrules for 1/16 in. O.D. tubing, and two 2 µm frits.. Material: 316L stainless steel. Dimension: I.D. × O.D. × L 4.6 mm × 1/4 in. × 15 cm. Sold in each. . . Sigma-Aldrich 59101 Column Blank Kit for HPLC, 4.6mm ID, 1/4" OD, 15cm Length. Country of Origin : United States. Part Number : 1179V53EA. Pack of : 1.