Parker A-Lok 8BF8-ZY Nylon Compression Tube Fitting, Back Ferrule, 1/2" Tube OD Back ferrule of a ferrule set for providing a seal when compressed between two mating components Connects to tubing Nylon for strength, flexibility, and resistance to abrasion, crushing, and cracking Twin ferrule compression fitting for a leak-resistant seal in high-pressure applications For use with Parker A-Lok FF-ZY series front ferrule (sold separately)