Stainless steel filter with a 0.5 micron frit that protects HPLC columns while maintaining excellent column performance. Easily installs on any column and is leak tight to 15,000 psi. Recommended for Velox 2.7um and 5um, Scepter 3um and 5um. For Velox 1.8um, Scepter 1.9um, XR-ODS, XR-ODS II and III columns, use the UltraShield with a 0.2um frit, REST-25810 (5/pk.)