High-performance liquid chromatography (HPLC) tubing offers efficient performance at high operating pressures in exacting environments. Its ability to withstand high pressures makes it an ideal choice for capillary HPLC and LC/MS. The tubing has a very smooth inside surface for excellent flow characteristics, with a low coefficient of friction, which leads to improved reproducibility and resolution and higher efficiency. HPLC tubing can be either stainless steel or silica-lined PEEK plastic—the stainless steel variant is required for ultra high pressure applications where plastic will not work.