Stainless steel, Avantor® ACE® guard cartridge holders are used for connecting guard cartridges to the LC column which then provides column protection and can extend the lifetime of your column. Holders are required for all Avantor® ACE® guard cartridges. Stand-alone holders require the use of a suitable connector often known as a column coupler. Avantor® ACE® guards and filters Protection of columns from 1.0 mm to 30 mm ID No loss in column performance or selectivity Significantly extends column lifetime Available in cost-effective multipacks Available for most phases and dimensions The use of a guard cartridge is recommended to protect the column from both frit blockage and irreversible sample adsorption. Without the use of a guard, column fouling can lead to increased column backpressures, peak splitting and/or tailing. It is generally recommended that guard cartridges should be replaced when the column backpressure increases by 10% or when column resolution or efficiency decreases by 10%.