Parker A-Lok 4FF4-B Brass Compression Tube Fitting, Front Ferrule, 1/4" Tube OD Front ferrule of a ferrule set for providing a seal when compressed between two mating components Connects to tubing Brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability Twin ferrule compression fitting for a leak-resistant seal in high-pressure applications For use with Parker A-Lok BF-B series back ferrule (sold separately)