Standard particle sizes are 3 and 5 μm. Analytical columns are available in 2.1, 3.0, and 4.6 mm diameters; standard lengths are 50, 100, and 150 mm. Capillary formats are available in 75 and 300 μm, 1.0 mm, and custom diameters, and in 50, 150, or 250 mm lengths. Micro precolumn and nano precolumn cartridges are available in several formats. Guard columns in both 2.0 and 4.3 mm sizes packed with 5 μm particles are recommended to protect analytical columns. Columns for fast LC are listed in the RSLC section.