Protect sample injector valves from particles shed through normal pump piston seal wear, and columns from premature plugging. Inline Filters: The filter holder is available in 316 stainless steel or PEEK. Inlet and outlet connections are compatible with Parker, Swagelok, Valco and Upchurch; 1/16" connections. The PEEK filter has a hand-tight design that requires no wrenches. Precolumn Filter: The precision manufactured 316 stainless steel holder incorporates a through-hole and dispersion cone geometry for minimal band spreading. Inlet and outlet connections are compatible with Parker, Swagelok, Valco and Upchurch; 1/16".