Protect Your Investment - Hamilton guard columns protect analytical, semi-prep and preparative HPLC columns. They also remove particulate contaminants and highly adsorptive compounds from samples, prolonging column life. The designs are modular and cartridge replacement is easy and tool-free. Cartridge holders for analytical columns are available in stainless steel and PEEK materials. Semi-prep/preparative holders are available only in stainless steel. The design of the cartridge holders is optimized to reduce dead volume and prevent extra column band broadening. Cartridge holders are reusable indefinitely.