HOLLOW RECTANGULAR CAPILLARIES MANUFACTURED IN BOROSILICATE GLASS, ID: 0.40mm x 4.00mm, Wall thickness 0.28mm +/-20%, ID Tolerances +/- 10%, Open both ends. Supplied in plastic vials - Each vial contains 25 capillaries. Available in 50mm, 100mm, 300mm and 600mm lengths. Part numbers 2540-050 (2540-50), 2540-100, 2540-300, 2540-600, RT2540.