Flash Pure Select cartridges are packed the highest quality silica designed to help maximize performance on any Flash purification instrument. Flash Pure Select cartridges are designed for superior performance with small, spherical particles. Flash Pure Select silica cartridges are filled with 15 ?m spherical particles for the ultimate and unmatched performance in a Flash chromatography cartridge. Flash Pure Select funcationalized silica cartridges such as C18, amino and Diol are packed with 30 ?m spherical silica.